Kamis, 28 Februari 2013

Mercury Grand Marquis Alternator Troubleshooting

Mercury Grand Marquis Alternator Troubleshooting

The Mercury Grand Marquis is a heavy, full-sized, V-8 sedan that seats six passengers. Though the Marquis lacks many of the features of modern luxury vehicles, such as a premium sound package and navigation tools, it does come standard with a leather interior, 17-inch alloy wheels and an automatic dimming rear view mirror. When the alternator in your Marquis begins to weaken or experience problems, you'll notice a lack of power and difficult cranking as it's the alternator's job to supply the battery with charging power.

Instructions

    1

    Test the alternator with a voltmeter. Clamp the voltmeter's positive lead to the positive battery post and the voltmeter's negative lead to the negative battery post. The positive and negatives are color-coded for easy identification: the positives are red, and the negatives are black.

    2

    Crank the engine and check the reading on the voltmeter. An alternator that's producing the right amount of energy will show a reading of between 13.6 and 14.3 volts. If the voltage is lower, it requires further testing at an auto parts store.

    3

    Inspect the alternator for signs of aging and wear, such as corrosion or damage.

    4

    Check the connections of the battery cables to the battery posts. Make sure the connections are secure and that there is no corrosive buildup. Even a healthy alternator will wear down quickly trying to deliver electricity through faulty connections.

    5

    Listen to the alternator while the engine is running. A noisy alternator can indicate a loose or bent pulley, shorted diodes or bad shaft bearings.

Rabu, 27 Februari 2013

How to Troubleshoot a Blinking Oil Light on a Honda Civic Hatchback

The Honda Civic hatchback is a well known Japanese car with a reputation for operating smoothly with few hassles. It is important to always keep an eye on the status of the oil in your car to keep the engine from blowing out. If you find yourself driving down the road and the oil light comes on, you will benefit from this guide outlining how to troubleshoot a blinking oil light on a Honda Civic hatchback. These procedures should take you about a half hour to accomplish.

Instructions

    1

    Take the car off the road and park it in a safe area and on a level surface. Turn the engine off.

    2

    Lift up the hood to see check the oil level. Remove the dipstick, identified by its looping orange handle. Use a rag to wipe the oil from the dipstick.

    3

    Slide the dipstick back into the tube. Wait at least five seconds, pull it out again and check the markers on the metal part of the stick to determine the oil level. Add oil if the reading is below the lowest mark or even with it.

    4

    Take off the engine oil fill cap by unscrewing it. Place it in a safe spot where you will remember it.

    5

    Place the funnel at the mouth of the fill tube. Pour Honda recommended motor oil into the funnel. Screw the oil fill cap back in place.

    6

    Check the oil level again after a couple of minutes. If the oil level is still low add more. Don't let the oil volume get above the highest mark because this can damage your engine. Too much oil will result in foam as the rotating crankshaft in the engine adds air to it. Oil that is filled with foam will be difficult to pump and can shut down the engine.

    7

    Turn on the car and pay attention to the oil pressure light read out. If it still blinks, you might have a more complicated and potentially serious problem. In this case, have your Honda Civic hatchback towed to a mechanic for his inspection.

Senin, 25 Februari 2013

Symptoms of a Wheel Out of Alignment

Symptoms of a Wheel Out of Alignment

Wheel alignment is a part of routine car maintenance. Contrary to the name, wheel alignment does not involve the wheels themselves but rather the vehicle's suspension system. Four factors affect alignment: caster, camber, toe and height. Caster is the angle of the axis. Camber is the degree to which the wheel tilts. The parallel between the car body and wheels is called the toe. And the height determines the space between the car body and road.

Difficulty Steering

    Wheels that are out of alignment can buckle under the weight of the car and refuse to turn. While driving ,your steering wheel may pull to one side, seem stiff or lock . The car may drift to the side of the road. Sharp turns and uphill routes in particular will reveal this symptom. Adjustments to the caster and toe are the necessary repairs.

Tire Wear

    Feathered, shoulder and uneven wear to tire treads is a sign of misalignment. Since the seat of each wheel is different, the weight of the car is unevenly distributed and contact with the road varies. Both distribution and contact affect the pattern of tire wear. Premature wear to either the front set, rear set or individual tires may also be a sign of wheel alignment trouble.

Visible Misalignment

    Wheels that are severely upset will be visible to the naked eye. Park the car so that the axis is as straight as possible. Examine the camber by standing 5 to 10 feet in front of the car and looking at the wheels head-on. Use a level to create a vertical in your line of sight. Compare the wheels to the level. Repeat with the back tires.

    Check for insufficient or excessive height by walking around the entire car and examining the body. Low height can cause paint wear and dents. Since a high frame may not bear damage, check the wheel wells for excessive wear and tear caused by overexposure.

Vibrations/Scraping

    A dropped height can cause the car's body to scrape against the road. This may cause noticeable vibrations, grating, scraping or sparks when driving uphill or on uneven roads.

Steering Wheel

    A crooked steering wheel (i.e. the center is not at the highest point) while driving straight comes from misaligned wheels sitting at a diagonal. This indicates a need for toe and camber adjustments.

How to Locate the Electronic Control Unit Ignition Module Computer Brain Box in a 1990 Dodge D150

The PCM or powertrain control module in your D150 is a small computer that acts as a brain for your truck's electrical system and various mechanical components. Every action that your truck performs, from braking to simply turning on the windshield wipers, is controlled and monitored by the PCM. The number one cause of damage to your D150's PCM faithfully attributes to electrical failure. Crossed wiring, vehicle accidents or merely hooking up the battery incorrectly can cause this. You can locate your 1990 Dodge D150's powertrain control module right at home. If you have to remove the PCM, expect to spend 20 to 30 minutes doing so.

Instructions

    1

    Raise the hood on your D150. Stand on the passenger's side of the engine compartment on the hubcap side of the front tire. You should be looking across the engine.

    2

    Locate the blower motor against the firewall to your immediate left. It resembles a medium sized, black metal can. Just below and to the left of the blower motor you should see a large plastic rectangular shaped box. The box also has a large 60 pin wiring harness connected to it that's held in place with a single bolt. This is your Dodge D150's powertrain control module.

    3

    Disconnect the negative cable from your D150's battery with a socket wrench before you attempt to remove the PCM. Remove the bolt holding the wiring harness onto the PCM with a socket wrench. Remove the two bolts on the left, upper and lower side of the powertrain control module with your socket wrench. Remove the single bolt on the lower, right side of the PCM with your socket wrench as well. Lift the powertrain control module out of the engine compartment using both hands.

How to Test an Automobile Computer

How to Test an Automobile Computer

An automobile's central computer is typically identified as a powertrain control module, electronic control module or electronic control unit. Testing any version of your car's computer requires the same diagnostic procedures used for pulling trouble codes from the vehicle's On-Board Diagnostic system.

Instructions

    1

    Compile a resource list before running diagnostics on your automobile. Look for two groups of OBD-II codes. Your OBD-II scanner's operations manual will feature an appendix or chapter on trouble codes; it lists generic trouble codes used by all post-1996 automobiles.

    2

    Locate a second set of OBD-II codes. These codes are determined by your vehicle's brand. Each manufacturer uses a separate set of supplemental codes. Some manufacturers are grouped together into corporate families. For example, General Motors encompasses Chevrolets, Buicks, and Oldsmobile. Chrysler covers Jeep, Dodge, and Chrysler brands. Find these codes online (See Resources).

    3

    Open the driver's side door. Place your code resources on top of the dashboard. Find the 16-prong receiving-plug outlet located in the leg-space area This port is called a Data Link Connection; its location will differ by brand, model, and year. It is typically uncovered, and to the lower left or the right of the steering column. DLC locators are available online (See Resources).

    4

    Connect your OBD-II scanner to its diagnostic cable. Insert the cable's 16-prong plug into the DLC outlet. Switch the scanner on, if it is not a brand that features auto-activation.

    5

    Put your key into your automobile's ignition and turn to the "On" position. Leave the engine off. This brings up your automobile's electrical system, and powers the vehicle's PCM, ECM or ECU. For some OBD-II devices, the electrical system may not be enough. Some handheld scanners require a running engine.

    6

    Look at your scanner's display screen. Check that your device is interfaced with the automobile's PCM, ECM or ECU. Consult your manual, and follow the exact instructions on how to enter a "scan" command. The procedure will vary by device.

    7

    Look at your scanner's display, and scroll through the alpha-numeric codes. Write down all the codes that are classified as "trouble." Your scanner's manual explains the difference between "trouble" and "pending" codes. Not all of these codes deal with your automobile's computer.

    8

    Retrieve your coding resources off the top of the dashboard. Look up all the relevant coding definitions; copy them next to the alpha-numeric numbers on your list. Place asterisks next to everything computer related.

    9

    Take your automobile to a mechanic if you verify any problems with your vehicle's computer. PCM, ECM or ECU modules are one complete unit. Fixing or repairing usually consists of replacing, restarting or reprogramming them. The computer module may be obsolete on older vehicles.

Minggu, 24 Februari 2013

When to Change an Idle Air Control on a 2001 Windstar

The idle air control (IAC) valve on a modern car maintains the engine idle when the throttle is closed. Used by all manufacturers, the IAC valve was replaced when electronic throttle bodies and drive-by-wire systems began to proliferate in the mid to late 2000s. Over time, a IAC can degrade or become fouled with oxidation, thus requiring cleaning or replacement. If you own a Windstar, a minivan made by Ford from 1995 to 2003, you may need to change the IAC.

Location of the IAC

    The IAC is attached to the throttle body. If you open the hood of your 2001 Ford Windstar, you will see the throttle body is located in the upper right corner of the engine bay, int front of the driver's position. The throttle body is connected to the intake manifold on its left and the air filter intake tube on its right. The IAC itself is a large metal housing with a two-prong electrical sensor connected to the throttle body with two small bolts. It sits right on top of the throttle body.

Symptoms of a Bad IAC

    The main symptom of a bad IAC is extremely poor idling. The vehicle may stall after it is started unless you keep your foot on the throttle. Once warmed up, the engine may hold idle but will bog down or stumble when you come to a stop.

Repair

    To remove the IAC for repair, disconnect the electrical sensor at the the end of the housing, and then remove the two retaining bolts. If you flip the IAC over, you will see that it is a plunger on a metal rod. You can use throttle body cleaner to soak the plunger assembly and clean the rod. Clean the electrical connection to the wiring harness as well, and use a dab of electrical-grade silicone to lubricate the connection terminals. This may restore the IAC's function, particularly if your Windstar has high mileage.

Replacement

    You can purchase a replacement IAC from your local Ford dealer or an automotive supply parts store. Simply unclip the electrical connector and remove the two retaining bolts. Remove the old IAC and insert the new unit. It may take a few starts before the new IAC is fully calibrated.

Can Water Get in Oil From a Blown Intake Gasket?

Can Water Get in Oil From a Blown Intake Gasket?

The automotive intake manifold functions as a passage to route atomized fuel into the cylinders for purpose of combustion. The intake manifold requires a gasket to seal the manifold against the cylinder head. On V-type engines that bolt and seal directly to the head, a fiber or metal-fiber gasket makes the vacuum and fluid-resistant seal. These types of engines have water passages, typically running from the front and rear of the intake manifold that circulates coolant. Under certain circumstances, water can enter into the oil pan as a result of a blown intake manifold gasket.

Intake Manifold Location and Design

    On the V-type engines, intake manifolds are made of cast aluminum, iron and, in some cases, plastic. They sit directly mid-engine between the heads. The manifold has two angled mating surfaces, one for each head bank. Large bolts must be properly torqued to specifications to connect and seal the intake manifold to the cylinder head. The intake manifold gasket has rear and front water passages, joining the manifold with the head, to allow coolant to flow and cool the cylinder head, as well as large fuel port openings and bolt holes.

Water in Oil Symptoms of a Blown Intake Manifold Gasket

    A blown intake manifold gasket shows itself by the condition of the engine oil when checked with a dip stick. If the vehicle has an oil leak, the oil will also appear altered in color and texture. Water-contaminated oil will look light brown and exhibit a frothy or creamy texture the consistency of a milkshake. The frothy texture results from churning and air in the oil. Oil will not necessarily enter the cooling system with a blown intake manifold gasket.

Reasons for Gasket Failure

    Intake manifold gaskets are designed to crush upon the torque applied to them between the head and manifold, forming a seal. Temperature fluctuations during constant engine heating and cooling can warp the manifold contact surface and allow gasket leakage. Age can cause the eventual deterioration of the gasket material, allowing a split or break. Severe engine overheating can warp the manifold or head, causing leakage as well as burning the gasket material. Corrosion and rust in a water passage can weaken and disintegrate gasket material.

Location of Gasket Failure

    Engines that have a one-piece manifold-to-head seal without a lifter valley cover will leak on the inner edge of the gasket close to the coolant passage. Coolant will bypass the gasket seal and leak down into the lifter valley. The coolant will proceed to drop into the oil pan and collect there. Some model vehicles do not have such a passage, or have the lifter valley sealed off by a separate cover.

Gasket Failure Consequences

    When the intake manifold gasket breaks and allows coolant to mix with the engine oil, the oil becomes diluted and loses its viscosity. Depending upon the severity of the leak, the engine might run hot. The radiator or overflow coolant reservoir level will drop noticeably. Water-contaminated oil will raise the engine temperature through increased friction. Connecting rods, crankshaft bearings, camshaft bearings, valve train rockers and shafts, valve stems and other major metal components will begin to fail. Water-contaminated oil leads to eventual seizing, galling and breakage of major engine components.

Sabtu, 23 Februari 2013

Symptoms of a Bad Brake Booster

Symptoms of a Bad Brake Booster

Because of the prevalence of disc brakes, power-boosted braking systems now come standard on nearly all new automobiles and recent-model used vehicles. Disc brakes are not self-energizing like drum brakes, so they require a power brake booster to keep pedal effort reasonable for all drivers. But like any human-made device, power brake boosters can go bad.

Booster Failure

    The primary symptom of power brake booster failure is a high, hard pedal that requires greater than normal pedal pressure to stop the car, according to the SouthernRods.com auto performance website. You may also notice that it takes a much longer distance than normal to stop your acar The high, hard pedal and longer stopping distance mean you are not getting power boost.

Proper Function

    A properly functioning power brake system should provide power assist on first application of the brakes every time, with normal pedal travel, pedal pressure and stopping distance, according to SouthernRods.com. However, if your brake pedal is low, spongy, requires pumping or fails under steady pressure, the brake booster likely is not at fault. These are indications of other serious problems in your braking system that require prompt attention.

Testing Booster

    Most power brake systems in autos are vacuum-based, using the difference between engine intake vacuum and atmospheric pressure as their power source, according to SouthernRods.com. To test your brake booster, pump the brakes several times with the engine off to deplete stored vacuum. Turn on the engine while pressing lightly on the brake pedal. You should feel the pedal fall away a bit and then become firm, but not hard. If you feel nothing at the pedal when the engine starts, your brake booster is not functioning.

Another Test

    Booster problems may indicate failure of the booster unit itself or problems in the vacuum system that powers the booster. A vacuum system problem may leave you with only partial boost, according to SouthernRods.com. To test for vacuum problems, start the engine and run it to medium speed, then turn off ignition and take your foot off the gas. Wait about a minute and a half and then apply your brakes. You should feel the vacuum boost on at least two brake applications. If you do not, you may have a vacuum system leak or bad vacuum check valve.

Signs of a Worn Out Alternator

The alternator is the component which operates the entire vehicle's electrical system. The alternator powers the battery, the engine, the computer system and the lighting. For this reason, it is important to recognize when the alternator is failing and have a professional mechanic examine the vehicle to confirm the problem. Fortunately, alternators rarely stop working immediately, and there are some common symptoms to look for.

Frequent Dead Battery

    A battery that frequently requires recharging is the most common symptom of a defective alternator. However, the problem may also be the battery rather than the alternator, particularly if the battery is old. Inspect the metal contacts at the top of the battery for green-colored corrosion. Clean the terminals with a battery brush. In such a scenario, both the battery and the alternator may be in working condition, but the corrosion could be preventing the alternator from properly charging the battery. If the problem persists, consult a mechanic.

Alternator Noise

    As the engine runs, the alternator's drive belt rotates the alternator's internal components via the pulley on the front of the alternator. To prevent the alternator from quickly overheating due to friction, the alternator has a number of bearings. If a grinding noise emanates from the alternator, chances are good that a bearing is damaged, and the alternator is defective. If instead a screeching noise is produced, the noise is likely caused by a loose alternator belt rather than from a problem with the alternator.

Negative Ammeter Reading

    The vast majority of vehicles are equipped with an ammeter gauge. The face of the gauge is divided into two halves. The right half notes positive current, and the left half notes negative current, meaning the absence of current. If the gauge reads to the left, the problem could be the alternator or the voltage regulator. Consult a mechanic who will quickly be able to determine the source of the problem with specialized tools.

Problems With Brake Override

Problems With Brake Override

Brake override is a relatively recent technology used by several carmakers such as Toyota. The technology uses sensors and electronics to engage the brake if the automobile accelerates suddenly. Most of the problems found with the brake override system stem from issues with the electronics and sensors.

Sensor Problems

    Brake override engages the brakes once the speed sensor or override sensor determines that the acceleration of the automobile is not under control. This problem became prevalent in Toyota vehicles that accelerated unexpectedly even when the driver was pressing the brakes. When one of the sensors fails, the brake override system may not work or may engage under normal driving conditions. Failing to replace the brake override sensor or the speed sensor to correct this brake override problem may lead to an accident.

Computer Not Programmed

    The automobile computer controls the sensors and monitors the gas pedal and the brake pedal. Once the computer determines the driver is pressing brake and gas pedals at the same time, the car's computer engages the sensors and the brake override takes control of the vehicle. If the computer in the car is not programmed properly, the brake override does not work, and sudden acceleration can occur unexpectedly without the brake override engaging. Take the automobile into the dealership to have the computer reprogrammed to correct this brake override problem.

Brake Problems

    As of 2010, brake override is one of the new safety features that could become a mandatory requirement on all automobiles in the future, but the brakes have been affecting the brake override system. Brakes use brake fluid, calipers, brake pads and rotors to stop the automobile. Most vehicles have antilock braking systems (ABS), which prevent the brakes from locking up when engaged. Worn brake pads, misaligned calipers, cracked or glazed rotors or malfunctioning ABS electronics will affect the the brake override system. The automobile can skid, cause longer stopping distances or engage one brake without engaging the other brakes when required. You must locate and repair the source of the brake problem to correct this override issue.

Jumat, 22 Februari 2013

How Do I Troubleshoot the Diagnostic Lights on a 1999 Volvo S70?

How Do I Troubleshoot the Diagnostic Lights on a 1999 Volvo S70?

The 1999 Volvo S70 is a luxury sedan with seating for five. The interior is spacious, providing almost 3 feet of legroom in the back and more than that in the front. This front-wheel drive car comes standard with a 2.5-liter engine and five cylinders. If the diagnostic lights, located in the dash cluster, are on, it's time to pull the diagnostic codes. Codes are created when a malfunction is identified in the engine and stored for your retrieval.

Instructions

    1

    Park the Volvo and turn the engine off. The diagnostic sequence will not initiate with the engine running.

    2

    Look under the driver's side dash for the test link, or Assembly Link Diagnostic Link (ALDL). This is an electrical port a little larger than a small box of matches. The ALDL has 12 to 16 open ports and may have a plastic cover protecting it. Remove the cover.

    3

    Connect the test lead end of an OBD-II scanner to the ALDL. Turn the scanner on.

    4

    Turn the key in the ignition until the dash panel lights up but before the engine cranks. A series of questions will appear on the scanner screen, asking you to identify the make and year of your car. Answer each of them in turn.

    5

    Select the choice to pull the diagnostic codes. Write down each one so you can reference them in your owner's or service manual. There are many different diagnostic codes, each referring to a specific problem detected in the engine.

    6

    Fix the problem found by the computer then retrieve the diagnostic codes again. Choose the option to reset the codes after they appear. This will clear them from the computer.

How do I Troubleshoot the Security System on a Silverado?

How do I Troubleshoot the Security System on a Silverado?

Chevrolet's Silverado range of pickup trucks may include a factory-supplied security system. The system consists of an antitheft alarm coupled with an immobilizer. The alarm is operated with the vehicle's remote transmitter, and the immobilizer is automatically, passively armed when the key is removed from the ignition. Problems with the two elements can include issues with keys and transmitters, and the system's not working as expected. These kinds of problems can be rectified through troubleshooting.

Instructions

    1

    Use the remote transmitter to operate the alarm system if the 10-second pre-alarm is activated when you open the locked driver's door with a key. The pre-alarm is telling you that you need to place the key in the ignition and turn it to the "Start" position. The pre-alarm consists of a chirping horn and flashing lights.

    2

    Change the batteries in the transmitter if the button presses don't activate or turn off the alarm system, or if the doors don't lock and unlock. Separate the transmitter by inserting a flat-head screwdriver along the center line and twisting. Insert a new battery.

    3

    Make sure that you are using the correct key, and turn the ignition off and try again if the engine won't start and the security light comes on the instrument panel. The immobilizer works by starting the vehicle only with a key matched to the ignition electronically. Keep gasoline pass keys and other electronic payment keys away from the Chevy key to avoid interference. Try another ignition key, or have a new key programmed if you continue to run into problems.

How to Troubleshoot Fuel Pump Problems for a 2002 Chrysler Sebring

Chrysler is the manufacturer of the mid-size sedan Sebring. Without the proper fuel injection components, your Sebring will not run. A major component of your fuel injection system is your Sebring's fuel pump. Located in the rear of your Sebring, your fuel pump is next to your fuel tank. Occasionally, problems will occur with your fuel pump which will render your vehicle inoperable.

Instructions

    1

    Strap your safety goggles on. Pop the hood of your Sebring. Prop the hood with the strut latch under the hood of your Sebring.

    2

    Connect your spark plug tester to a spark plug wire. Ground the spark plug tester to the frame of your Sebring, this will enable a good electronic reading.

    3

    Start your Sebring. If your vehicle does not start, but a spark is read from the spark plug tester, then your fuel ignition system is defective.

    4

    Disconnect the spark plug tester. Turn off your Sebring.

    5

    Raise the rear of your vehicle with your car jack. Place the drain pan underneath your fuel tank and drain any fuel in the tank.

    6

    Remove the fuel tank. Two straps hold the fuel tank in place, with four bolts attaching the straps to the frame of your Sebring. Use your socket wrench set to remove the bolts, straps, and fuel tank.

    7

    Inspect the wire connections of your fuel pump. Your Sebring's fuel pump will be attached to your fuel tank. Check the wire connection for rust, corrosion, or any other damage. If no damage is visible on the wire connection, your fuel pump device is defective.

What Causes the Check Engine Light to Come on in a 2001 KIA Sephia?

When the check engine light illuminates in the 2001 Kia Sephia, it is an indication that there is a problem in the vehicles emission system. Often mistakenly misinterpreted as a fault in the engine or transmission from a mechanical standpoint, the light, intimidating due to its location, does not necessarily denote an emergency. If the Sephia is running well, correct the problem at a more convenient time. The engine management computer sensed an irregular signal from one of its sensors or activators. When this happens, it records the fault in memory and encrypts the fault to a code. A simple inexpensive code scanner available at any auto parts store will retrieve the code and provides an explanation of the fault.

Instructions

    1

    Plug the code scanner into the on-board diagnostics, or OBD port located under the dash just to the right of the steering column. Turn the key to the On position with the engine off.

    2

    Depress the key marked Read. The computer will display a five-digit code, a letter followed by four numbers. Make a note of this code or codes if more than one.

    3

    Cross-reference the code with the code sheet and an explanation will be offered depicting the part at fault and why.

    4

    Correct the fault so the code can be erased and the light extinguished. Turn the ignition key to the On position and depress the key marked Erase. The codes will be erased and the light turned off until the next failure.

How to Test a Wheel Speed Sensor

How to Test a Wheel Speed Sensor

Most vehicles today have anti-lock brakes. The wheel speed sensor works in conjunction with the anti-lock brake system by interpreting the rotational speed of the tire through a magnetic signal. The wheel speed sensor can tell if a tire stops rotating or locks up, and it sends that signal to the anti-lock brake system so it can relieve pressure and allow the wheel to turn. Wheel speed sensors mount on each wheel to record individual wheel speeds, and activate a signal after the car is traveling at approximately 3 to 5 mph. Since the signal sends an electronic pulse, you can test the wheel speed sensor with a multimeter.

Instructions

    1

    Park the vehicle and turn off the engine with the transmission in "Park" or neutral. Set the emergency brake.

    2

    Locate your vehicle's main fuse block. Refer to your owner's manual for its location. Look in the engine compartment, driver's side kick panel or in the glove box. Remove the fuse block lid and locate the ABS fuse. Make sure the filament inside the fuse appears intact; replace if necessary.

    3

    Loosen the lugs on all four wheels with a tire iron -- do not remove the lug nuts. Lift the front of the vehicle with a floor jack and place two jack stands under the frame near each wheel. Lift and support the rear of the vehicle in the same way. Finish removing all the lug nuts with the tire iron, then set the wheels aside.

    4

    Release the emergency brake and set the gearshift in neutral. Sit down underneath the front wheel well and look for a wire coming from the wheel speed sensor mounted on the rotor, CV joint or wheel hub. It will look like a small plastic box. The wire will lead up through the fender well. Disconnect the wire at the jack by pulling it apart with your fingers. Look at the two-pin connector.

    5

    Set a multimeter to measure resistance (ohms). Place each probe of the multimeter on each pin inside the connector. Connect it to the end of the wire that comes from the sensor. Note the ohm reading on the gauge. Have an assistant manually rotate the wheel hub as fast as he can while you hold the probes in place. See if the ohm number changes with the spin of the wheel. Any change in ohms indicates a good connection to the sensor. No change indicates a broken or shorted wheel sensor wire.

    6

    Switch the multimeter setting to the volts scale, 10 volts maximum. Insert a flying lead between the two wire connections. Flying leads have extensions that plug into the female side and the opposite male side, with some bare metal exposed, so you can probe both wire sides with the jack connected. Place one lead from the multimeter onto one flying lead, and the other probe to the other flying lead.

    7

    Have your assistant turn the ignition key to the "On" position. Look at the voltage reading on the gauge. Normal voltage will be between +5 or +12 volts, depending upon the ABS specifications. Refer to your owner's manual for the exact number. With the key still on, have your assistant rotate the wheel hub again. If you see a voltage change, the wheel speed sensor functions properly. If the voltage does not change you have defective sensor.

    8

    Check the rest of the wheel speed sensors on each wheel with this same procedure. Any difference in the ohm or voltage readings on a wheel will indicate either a wire break, short or a defective sensor. Be certain to reconnect all the wheel speed sensor jacks when finished. Mount the wheels on the vehicle and use a tire iron to partially tighten all the lug nuts. Use the floor jack to lift the vehicle and remove the jack stands. Use a torque wrench to tighten all the lug nuts to manufacturer's specifications.

Kamis, 21 Februari 2013

Why Does My 1990 Chrysler Lebaron Lurch?

The third generation -- 1987 to 1995 -- LeBaron was something of an oddity for a model of such historically large proportions, but its stature was fairly in keeping with the design standards of the time. The third generation LeBaron came with a variety of engines, including the Mitsubishi 6G72 V6 and a number of 2.5-liter and 2.2-liter engines. While all were fairly stout from the factory, the fact is that their sensors, electronics and hardware are more than 20 years old and are bound to cause a few problems from time to time.

Vital Sensors

    While pre-1996 engines don't use quite as vast an array of sensors as their newer offspring, those that they do use are vital. The most important are the crankshaft/camshaft position sensor, the throttle position sensor, oxygen sensor and throttle position sensor. Most of these sensors don't fail outright, they fail intermittently and begin sending incorrect voltage readings to the computer. These intermittent readings confuse the computer, causing it to continuously adjust the air fuel mix to stay within its programmed parameters. This continual adjustment can result in lurching under cruise or acceleration.

Transmission Fluid Level

    Chrysler transmissions of this era are very sensitive to changes in transmission fluid level, and don't like being run dry. The transmission dipstick has two or three markings: cold, warm and hot. The "cold" marking indicates the lowest acceptable fluid level, and "hot" indicates where it should be under running conditions. If you fill the transmission to to "cold" when it's hot, the transmission pump will start sucking air and starve the torque converter and fluid passages of fluid. This can easily result in a lurch accompanied by a rise in engine rpm. Remember to always check you transmission fluid on level ground, not on an angled driveway.

Shift Failure

    This isn't a failure of the transmission so much as it is of the shift mechanism in the steering column. Many Chrysler K- and J-body cars of this era (including the LeBaron, Aries, Reliant, Dynasty and a number of minivans) developed column shifter issues, wherein the car would either refuse to engage overdrive or would slip into and out of it. The resultant lurch was either a result of the engine hitting the rev limiter in third gear or of the transmission repeatedly going into and out of overdrive. The only permanent solution here is to take the steering column apart and repair the shift mechanism.

Vacuum Leaks

    A number of transmissions from this era used a vacuum-actuated modulator that uses engine vacuum to control fluid pressure and shift firmness. If your vacuum line is leaking or cracked, the transmission may receive an intermittent vacuum signal and continuously adjust fluid pressure to compensate. Once fluid pressure goes up, the engine engages more fully and vacuum drops. Once vacuum drops, the leaking hose allows the pressure inside the line to equalize to atmospheric pressure and the transmission fluid pressure goes back down. This pressure fluctuation can manifest as lurching under cruise conditions.

Boost Fluctuations

    Many LeBarons of this era rolled out of Chrysler's Delaware and Missouri plants with turbocharged engines. Turbo pressure fluctuations can cause lurching just like any vacuum leak. These pressure fluctuations can come from a leaking turbo-to-engine tube, a leaking intercooler or a malfunctioning wastegate. Leaks in hard components like the intercooler will usually result in a general drop in boost pressure and horsepower, but leaks around soft rubber components can result in lurching. The wastegate is a boost-actuated valve that allows exhaust to bypass the turbo at a pre-set pressure level. The wastegate solenoid connects to the intake system via a rubber vacuum line; if this line develops a leak, the wastegate will open and shut repeatedly, leading to lurching and a shudder during acceleration.

What Causes Feathered Tires?

What Causes Feathered Tires?

"Toe setting" may seem like one of those obscure terms relevant only to engineers and mechanics, but it's actually quite germane to soccer moms, business travelers and anyone else who uses an automobile. The ability to read tire wear, including conditions such as feathering, is a key skill that almost anyone can acquire, and it may well save you more than money -- it could some day save your life.

Toe Settings

    The wheels on your car may look perfectly square with the car from a distance, but they're not. Tires both sit at and go through a whole range of angular movements: they tilt in or out at the top, move forward or backward with the suspension and angle inward toward each other, or outward away from each other, at the front. This last setting is known as the suspension's "toe" setting. "Toe-in" means the front of the tires point toward each other, and "toe-out" means that they point away from each other.

Toe Settings and Slip Angle

    You may wonder why a manufacturer would want your vehicle's wheels to point anything but completely parallel with each other; after all, that would offer the least rolling resistance and best fuel economy. But tires work best when they're slipping a little relative to the road. A slight slip angle keeps the tires warm and the tread sticky, while zero angle makes them cold and hard. Excess slip angles can overheat your tires at sustained high speeds, quite possibly resulting in tread disintegration or a blowout.

Toe Angle and Steering Dynamics

    Another reason for changing toe angle from the parallel is related to how it affects steering. Setting the suspension with a toe-in or inward angle causes the wheels to constantly steer toward each other, which makes that end of the car more stable and resistant to sudden changes in steering input. Angling the tires away from each other does the opposite: increasing steering response, but making that end of the car more unstable. At their extremes, toe-in can make the car handle like a dump truck and refuse to turn, while toe-out can make it darty and unpredictable.

Reading the Feather

    Feathering happens as a result of the tire's sideways slip. As the tire turns sideways, the road grinds on the tread, causing one side to wear faster than the other. Radial tires like those used on most cars tend to roll a little under excess toe, which means the side of the tread with more wear is the one facing the front of the car. Tire wear facing the outside of the tire indicates excessive toe-in, while feathering facing the inside of the tire indicates toe-out.

My Chevy Won't Go Upon Acceleration

My Chevy Won't Go Upon Acceleration

Gasoline engines require four things to run: a steady flow of fuel, air to burn the fuel, a spark to ignite the air/fuel mixture, and cylinder compression to make the air/fuel mixture volatile enough to burn. You'll need to take a systematic approach to diagnosing your Chevy, testing each of the engine's four required factors to find a malfunctioning component.

Instructions

    1

    Access your Chevrolet's fuel line, and locate the fuel pressure access port. Remove the cap that covers this port (often found on the fuel rail of fuel injected engines, or on the throttle body of throttle-body-injected engines). Screw the fuel pressure gauge's test end onto the access port and start the engine. Compare the reading to the pressure specs in your reference material to determine if you have adequate pressure.

    2

    Check the injectors. If you have a throttle body injected or carbureted engine, look into the engine's throttle plates to visually check that fuel is entering the engine. Multi-point fuel injection systems are more difficult to check; consider taking your car to a service center offering an injector cleaning service and see if that solves the problem. Otherwise, you'll need to remove the injectors to have them tested for adequate flow. If you have adequate pressure and fuel flow into the engine, proceed to the next step.

    3

    Connect a vacuum gauge to one of your Chevy's vacuum ports and start the engine. Your engine should read a steady 11 to 18 pounds of vacuum. A gauge that regularly fluctuates more than one to two psi indicates a loss of compression in one cylinder. If you detect a loss of compression then you'll need to check the cylinders one by one to find the problem.

    4

    Disconnect your engine's fuel injectors from the injection wiring harness; this will keep the engine from starting while you check compression. Remove the number one (driver-side-front) spark plug and screw the compression-tester end into the spark plug hole. Have an assistant turn the engine over while you watch the compression gauge. Compare your reading to the factory specification for your engine; it should be within ten percent of factory spec. A low compression reading indicates worn piston rings or cylinder walls, leaking valves or other internal engine damage/wear that will require a rebuild.

    5

    Plug the spark plug back into the plug wire, and hold the spark plug with a rag. Press the plug's tip against the cast bare metal of your engine block, cylinder head or intake manifold. Have your assistant turn the engine over while you watch the plug for spark. The spark should be regular, thick and bright bluish-white; an irregular, yellow-ish or absent spark indicates and ignition problem. If you do not detect an ignition or compression problem with that cylinder, reinstall the spark plug and proceed to test the rest of the cylinders. Remember to check the plugs themselves for damage, carbon build-up or oil fouling.

    6

    Once you determine which system or parameter is contributing to the power loss, work outward from the engine to find the exact component that's causing the malfunction. Compression losses always indicate a problem in the engine itself, but any other diagnosis will indicate an external component, sensor or engine ancillary malfunction.

The Consequences of Low Transmission Fluid

Your transmission is one of the most expensive and important parts of your vehicle. Replacing or rebuilding a transmission can cost thousands of dollars, so it pays to properly maintain your transmission. Low levels of transmission fluid can cause a number of long-lasting problems with your transmission and can shorten its working lifespan. You should check your transmission fluid regularly to make sure your transmission has adequate lubrication.

Not Shifting Properly

    Your transmission may start slipping or not enaging properly if you do not have enough transmission fluid. This causes your vehicle to shift poorly or slowly. If you have run your vehicle for an extended period with insufficient fluid, you may not be able to solve the shifting problem by adding fluid.

Overheating

    One of your transmission fluid's primary jobs is to keep your transmission from overheating. If you do not have enough transmission fluid, your transmission is likely to overheat and vital parts could burn up. If your transmission is overheating, a check engine light or its equivalent may appear on your dashboard, or your car may not shift correctly.

Total Failure

    Operating your vehicle without enough transmission fluid for a long period can cause your transmission to stop working. In that situation, your vehicle may not move or may only move in one direction or at a certain speed. If this happens, you must replace your transmission.

Reasons Why a Check Engine Light Is on in a 2005 Escalade

Reasons Why a Check Engine Light Is on in a 2005 Escalade

Originally based on the Chevrolet Suburban and GMC Yukon, the Escalade was GM's attempt at competing with Lincoln's up-market Navigator full-size SUV. The first and second generation Escalades were fully modern offerings, incorporating GM's variant on the federally mandated Onboard Diagnostics, Series II programming protocol. OBD-II is very good at finding faults in the powertrain and chassis, but the check-engine light that it controls can be a bit vague.

Triggering a Check-Engine Light

    The check engine light is your computer's first means of notifying you of a fault, but isn't necessarily its last. Vehicle sensors provide data that help the computer to monitor hundreds of different aspects of engine and transmission operation; they'll even tell the computer when they themselves aren't working properly, which is kind of a neat trick. If any of the sensor readings depart from what the computer expects, it'll trigger a check engine light to notify you that it's time to check the codes.

Throwing Codes

    The computers record problems and store them as five-digit alphanumeric codes. In 1996, the Federal government mandated that all manufacturers utilize this standard coding system -- called OBD-II -- so that state emissions inspectors wouldn't have to have a different scanner for every type of car out there. Anything remotely related to engine emissions or safety uses the generic OBD-II coding system. If your Caddy didn't come with the optional digital display that allows access to the engine trouble codes, get them checked free at your local auto parts chain store.

The Letter Meaning

    The computer's OBD-II code consists of four basic parts. The first is a letter indicating which system has experienced a malfunction. The most common is "P" for "powertrain," referring to the engine, transmission and everything that makes the truck move. You might also see "B" for "body" -- meaning anything to do with airbags, seatbelts, power seat function or anything else mounted to the vehicle body -- or "C" for "chassis." A chassis code indicates a fault involving the wheel speed sensors, suspension sensors, anti-lock braking system and anything else involved in making the vehicle stop or turn. The Society of Automotive Engineers designates "U" as "undefined," referring to anything that doesn't fit into any of the other categories.

The First Number

    The number just to the right of the letter -- a "0" or a "1" -- indicates a generic and publicly accessible code or a manufacturer-specific code, respectively. Generally a "0" code will show up on generic scanners while "1" codes won't. If you've got a check-engine light and the scanner fails to register a code, then the code is a GM-specific code that doesn't fall under federal emissions control or safety regulation. In these cases, you'll have to use a computer programmed with GM-specific codes or take your truck to a GM dealer service center. Most engine codes, however, will show up with the generic "0" prefix.

Third Digit Code Numbers

    This is where you get down to figuring out exactly what caused your check-engine light. The third digit in your check engine code tells you which vehicle system tripped the code. A "0" generally means there is a problem in the air- and fuel-metering systems that directly interact with vehicle emissions. A "1" indicates an irregularity in the amount of air or fuel going into the engine or an air-fuel sensor failure. A "2" tells exactly what's gone wrong in the air-fuel circuit, while "3" is an ignition system problem or cylinder misfire and "4" indicates a problem in the auxiliary emissions controls.

More Third Digit Number Meanings

    Numbers "5" through "9" generally indicate something that doesn't necessarily have to do with the engine itself, but may affect emissions, safety or fuel consumption in some way. A "5" in the third digit position indicates a problem with the vehicle speed control, idle control or air-conditioning system. The system uses "6" for the computer's self-diagnostics. Codes "7" and "8" indicate transmission problems. The Society of Automotive Engineers has reserved code 9 for use in any vehicle system they haven't thought of yet.

The Last Two Numbers

    The fourth and fifth digits of your OBD code are like serial numbers that indicate the specific fault in the system, so you'll need to look your specific code up online or at your local auto parts store to find out what the last two digits mean. There's no room to list them all here, as the current OBD coding system allows for 8,000 possible fault code listings. If you see a check engine light, get it diagnosed as soon as possible; letting anything go for too long is bound to affect another component before you get it fixed.

How to Troubleshoot a Battery Charge on a Jeep Liberty

One of the most important components under the hood of your Jeep Liberty is its battery. Without a fully charged 12-volt battery, the Liberty will not have sufficient cranking power to start. The battery itself may fail or discharge due to any number of reasons. Usually, if a new battery is drained, it is likely a result of a switch accidentally left in the "On" position. Otherwise, if the battery in your Liberty is more than four years old and you are repeatedly having problems with it, it may be time to purchase a new battery.

Instructions

    1

    Turn the Liberty's engine off, as well as all other accessories. Then turn on the Jeep's windshield wipers. If the wipers move at the correct speed, your battery should have a full or nearly full charge. If, however, the wipers do not move or move slowly, the battery will need recharging.

    2

    Attempt to start the Liberty's engine. If the motor cranks but does not start, the problem does not lie with the battery charge. If the motor simply churns and fades or you hear a clicking sound, the battery is likely dead and needs recharged.

    3

    Turn off the Liberty's engine and all electric accessories, such as the stereo and lights. Release the hood and pinpoint the battery within the engine compartment. To test the battery's connections and charge, you must take away any guards covering the battery and/or its terminals. Usually all that's needed to remove the guards is a small wrench or screwdriver.

    4

    Check the battery connections. If the clamps are loose, it may make it seem as though the battery isn't fully charged. Tighten the clamps if they're not secure. If the clamps or terminals are dirty, clean them with a wire brush.

    5

    Link your digital voltmeter to the Jeep's battery. In order to achieve a correct reading, be sure the positive and negative leads on the voltmeter are properly and securely attached to the corresponding positive and negative battery terminals. Remember, positive to positive, negative to negative.

    6

    Look at the voltage display on the voltmeter. If your Liberty's battery has at least a 70 percent charge, you will see a reading of approximately 12.4 volts. If the reading is any lower than 12.4, you recharge the battery with a battery charger. A full charge in your Liberty's battery will display a reading of about 12.6 or more volts on the voltmeter.

Rabu, 20 Februari 2013

My 2007 Altima Won't Beep When I Lock the Door

My 2007 Altima Won't Beep When I Lock the Door

The 2007 Nissan Altima is fast, powerful and comfortable. As well as being customizable and user-friendly, there are numerous small touches that make it a polished and fun-to-drive machine. Sometimes those small touches can lead to customizations occurring accidentally. This is often the case when setting the lock options. In the 2007 Nissan Altima, the Intelligent Key controls whether the car beeps upon locking or not. The control can easily be switched to the "no beep" option when the key is thrust into a purse or back pocket.

Instructions

    1

    Press the "Lock" button on your Nissan Ultima 2007 Intelligent Key remote. Be sure you are near your car, so you can listen for the beep upon locking.

    2

    Press and hold the "Lock" and "Unlock" buttons together. Wait at least two seconds. To confirm the horn has been reactivated, the hazard warning lights should flash three times.

    3

    Press the lock button to make sure the horn beeps once the car is locked. If not, repeat holding the "Lock" and "Unlock" buttons until the hazard warning lights flash.

Senin, 18 Februari 2013

How to Check the Mass Air Flow Sensor on a '94 Ford Taurus

Taurus' second generation, spanning from 1992 to 1995, rode quite a wave during its production run. With its modern looks, improved handling, versatility and usable power from the available 3.0-liter Vulcan and 3.8-liter Essex V-6 engines, the Taurus seemed poised for a takeover of the American family car segment. And it was quite successful for the most part, outselling most of its competition and even helping to launch America's compact sports car revolution when upgraded to SHO trim. The Taurus' mass airflow sensor was responsible for monitoring the amount of air going into the engine; sensor failure or dirt and junk on the MAF sensor wire can confuse the car's computer and result in both poor performance and fuel economy.

Instructions

    1

    Install the needle probes into your digital multimeter and set the DMM to read in volts DC. Turn the ignition key to the "On" position, but do not start the engine. Identify the four wires on your MAF sensor harness. From right to left, they are: 12-volt power supply, constant ground, ground supplied by the computer and MAF sensor output.

    2

    Poke the DMM's red probe tip into the right-hand wire on your MAF sensor harness, aka the 12-volt power-supply wire. You should get a reading of 12 volts. If you do not get a voltage reading, then the MAF sensor itself is probably fine, but isn't getting power.

    3

    Place the red sensor probe on the positive terminal of your battery and poke the black sensor probe into the black wire on your MAF sensor harness -- second to the right, the MAF sensor's constant ground. You should get a reading of 12 volts to the ground wire; if not, then the sensor isn't grounded.

    4

    Repeat the ground test with the second wire to the left, but be very careful. This wire is a ground provided by the car's computer, and accidentally shorting it can result in a fried computer. When probing the ECM ground wire, you should get a reading of 12 volts. If you don't get a reading, then the MAF isn't getting a ground from the computer.

    5

    Start the engine and get it up to its normal operating temperature. Now that you've established that the sensor is getting the appropriate power supply, you can test its actual output.

    6

    Connect your DMM's black probe to the negative battery terminal and probe the sensor wire output -- the last one on the left. Check the output in voltage; a bit of voltage fluctuation is normal, but it should remain fairly steady.

    7

    Rev the engine up slowly and watch the DMM's voltage reading. You're not looking for a specific voltage output at a given rpm as much as you are watching to ensure that the voltage rises and falls linearly with engine rpm. If you notice any random spikes, drops or gaps in voltage, the DMM reads zero voltage or stays stuck at one voltage, then you may have a defective MAF sensor.

    8

    Shut the engine off and remove the MAF sensor from the tube by removing the star-bit screws holding it in place. Examine the sensor wire to see if it looks fuzzy, dirty or contaminated. If it looks anything but shiny and new, spray the wire with some MAF sensor cleaner. You'll find it at any auto parts chain store.

    9

    Reinstall the MAF sensor and retest its voltage output. If output behavior hasn't changed and it still spikes, drops, lags or stays stuck at a particular voltage, then the MAF sensor is defective and needs replacement.

Computer Problems in a 2001 Oldsmobile Aurora

The Oldsmobile Aurora, a mid-size luxury car, was introduced in 1994. Edmunds.com contends that the redesigned 2001 Aurora is a solid combination of "style and value." Despite its positive reviews, the 2001 Aurora suffers from a faulty powertrain control module, which is the vehicle's computer.

Freeze Frame Data

    Oldsmobile technical service bulletins (TSBs) indicate that the 2001 Aurora suffers from a problematic powertrain control module (PCM), which regulates many of your vehicle's functions. In particular, your Aurora may experience a communication failure between the PCM and the on-board freeze frame, which provides diagnostic data about your vehicle.

Oxygen Sensor

    TSBs report that the PCM may also fail to communicate with the on-board diagnostic (OBD) oxygen sensor, which measures and regulates the amount of oxygen, fuel and nitrogen being emitted from your engine. Decreased fuel economy and poor engine performance are indicators of a failed oxygen sensor.

Solution

    PCM failure is usually indicated by an illuminated check engine light. Once detected, communication failure can be solved by PCM flash reprogramming. Reprogramming the PCM is a simple software update that improves communication and performance. It can be performed at your dealership or by a licensed mechanic.

How to Troubleshoot a Ford F-150 Engine

How to Troubleshoot a Ford F-150 Engine

Engines are complex and some components are hard to reach. Troubleshooting problems can be difficult, especially if you are dealing with an older Ford F-150 pickup truck that has had many years of wear and tear. One method focuses and streamlines the process. You can use the F-150's On-Board Diagnostics System for leads and make a list of targeted engine locations.

Instructions

F-150s Before 1996

    1

    Start the F-150's engine and let it run until it reaches its normal operating temperature. A running air conditioning will alter this somewhat, so make sure the A/C system is off. Once the engine is warmed, turn it off and wait

    2

    Open the hood and locate the Self Test Outlet and the Self Test Input. They will be toward the back end of the engine compartment. The Outlet is trapezoidal and has six sides; the Input is a small plastic port on a pigtail-style wire.

    3

    Connect the Outlet and Inlet with a jumper wire. The Outlet has two rows of slots. The bottom row only has two slots and the jumper wire should be connected to the one on the left.

    4

    Turn the ignition key to "On" but do not start the engine.

    5

    Count light flashes and pulses. Ford codes come in two numbers. The first will be a long flash and the second will be a shorter pulse. For example, code 27 will be represented by two flashes followed by seven pulses. A pause of a few seconds will occur between the trouble codes. Write down the code numbers and turn off the F-150 when you are done. Remove the jumper wire and close the hood.

    6

    Look up the coding descriptions online. They will not be in the F-150's manual. Copy the definitions next to the code numbers you have written down. Return to your F-150, open the hood and conduct a focused investigation.

F-150s after 1996

    7

    Plug your OBD-II scanner into the diagnostic outlet to the right of the steering wheel, beneath the dash. Turn the scanner on if it does not self-activate.

    8

    Insert your key into the ignition and turn to "On." You may have to crank the engine but that depends on the brand of scanner you are using. Scanners have different operating systems and button configurations. Always consult your scanner's handbook for the exact process your scanner requires.

    9

    Use the code-retrieval process outlined in your scanner's handbook. Some scanners automatically pull the codes but some need specific keys pressed. Once the codes appear on the scanner, compile a list. Place all of the trouble codes at the top of the list. These malfunctions have occurred frequently and should be investigated first. Put all the pending codes beneath the trouble codes. The pending codes might not have happened as often but they are still malfunctions and are worth investigating.

    10

    Turn the F-150 and the scanner off. Remove the scanner's cable from the diagnostic outlet. Consult your scanner's handbook for coding definitions. Your scanner will reveal only the general OBD-II codes used in all vehicles manufactured after 1996. Your F-150's manual will not feature Ford's supplemental codes. Those, however, can be looked up online. Once you have located all the coding definitions, add them next to codes on your list.

    11

    Open the F-150's hood and begin a targeted investigation. Start at the top of your list and cross off codes once you have eliminated them from consideration.

How to Check a Bad Coil

How to Check a Bad Coil

Coils have many different applications, ranging from relays (electric switches) to chokes in electronic circuits. The coil (ignition coil) in your car creates high-voltage electricity for the spark plugs. Your ignition coil is actually a transformer, made up of two coils. One coil has fewer windings of wire than the other coil. The coil with fewer windings receives a short burst of 12 volts of DC current (VDC). This coil transfers the 12 VDC pulse to the second coil and steps up the voltage to the required level.

Instructions

    1

    Turn on the ignition but don't start the car at this stage. Using a multimeter in the DC volt position, check for a 12 VDC supply coming to the coil's positive terminal. (This terminal should have a black wire leading to it.) If there is no voltage, consult the vehicle manual.

    If there is voltage, turn off the ignition switch and continue.

    2

    Remove the high-voltage wire from the center of the distributor cap.

    3
    Use a multimeter to check the coil.
    Use a multimeter to check the coil.

    Using a spark plug wrench or socket wrench, remove one spark plug from the engine. (If you have a spare spark plug, you can skip this step.)

    4

    Attach one end of a jumper wire (test lead) to the exposed metal at the end of the high-voltage wire and clip the other end onto the spark plug terminal. Ground the spark plug onto the engine body.

    5

    Attempt to start the engine while you watch for a spark across the gap of the plug. You should hear a snapping sound at the plug as well. Only a few turns of the engine will be necessary. Sparking across the spark plug gap indicates the coil is okay. The absence of a spark would make the coil suspect.

    6

    Remove the jumper lead from the plug terminal and high-voltage wire. Reinstall the spark plug, making sure to connect the spark plug wire back to the spark plug. Leave the high-voltage wire off the distributor.

    7

    Remove the 12 VDC supply wire from the coil.

    8

    Set the multimeter to the lowest possible ohm position and connect one of the meter probes to the terminal where the black wire was attached to the ignition coil. Set the other meter probe to where a green wire attaches to the coil. The resistance reading should be in the range of 0.3 to 1.7 ohms.

    A reading less than the lower reading could indicate a short, and no reading indicates an open coil. The low reading is not always a guarantee that the coil is faulty, but if the coil is open the ignition coil should be replaced.

    9

    Set the multimeter to a higher reading (10k ohm range) and attach one meter probe to the green wire terminal and attach the other one to the end of the high-voltage lead. A reading from 5,000 to 13,000 ohms would be normal, depending on the car. Any reading lower than the lower reading should be suspect, meaning there is a short somewhere in the coil. No reading would indicate a broken coil. In either case, the ignition coil should be replaced.

Minggu, 17 Februari 2013

How to Retrieve Trouble Codes for a Car 1995 & Older

1995 was the final year in which the original, 2-digit diagnostic trouble codes (DTC) were used. After '95, cars came equipped with multi-digit codes preceded with a letter, each indicating which part of the vehicle is experiencing a problem. Newer codes are more specific and require a scanner to pull. Older DTCs can be retrieved manually, using an ignition key and a bit of wire. Refer to your car's repair manual for the meanings for the codes.

Instructions

The "Key Dance"

    1

    Insert the key into the ignition and turn it on, without cranking the engine. You'll know you have it in the right position when all dash instruments light up and the radio works, but the engine isn't running.

    2

    Turn the key off, on, off and on again rapidly, usually within a 5-second period. End with the key in the "On" position, and watch the "Service Engine" light for codes. The light flashes several times for the first digit, pauses, then flashes several more times for the second digit.

    3

    Write the codes down and look their meanings up in a service or repair manual.

Alternative Methods of Retrieval

    4

    Locate the diagnostic test port under the dash. It's usually on the driver's side, though in some cars it's under the passenger side or under one of the seats. This is the port the scan device plugs in to. Connect ports "A" and "B" with a piece of jumper wire or an unbent paper clip. Watch the "Service Engine" light for the codes.

    5

    Look under the hood for the data link connector. It's in two parts, one with six electrical ports, and one with a single port. Turn the ignition key "On," then connect the links as shown in the diagram at sethirdgen.org (see References) with a piece of jumper wire or a paper clip. Touch a test light to the second port on the bottom row of the ports and watch for codes to flash from the bulb of the test light. This method works for Fords.

    6

    Press the odometer reset button while turning the ignition over. Don't crank the engine. The dash instruments will undergo a test, then the DTC's will appear in the odometer screen. This works on digital dashes.

How to Troubleshoot the Rear Brakes on '97 Chevy Astro

How to Troubleshoot the Rear Brakes on '97 Chevy Astro

Chevrolet first introduced the mid-size Astro van in 1985. If your rear-wheel drive 1997 Chevy Astro van is stuttering or unresponsive when you press the brake pedal, you can troubleshoot the rear brakes yourself in an empty parking lot by following some simple steps. You will not need any tools or special training, and should be able to sufficiently troubleshoot your Astro's braking system within an hour. Be sure that there are no pedestrians present as you test your Astro's rear brakes.

Instructions

    1

    Turn the ignition key on your Astro, shift into "park" or "neutral", and firmly press the brake pedal down. If the brake pedal offers no resistance when pressed down, there could be air in the brake lines or a low fluid level in the master cylinder. The brakes may also need adjustment, or the proportioning valve may need to be replaced. If the brake pedal offers uneven resistance when pressed down, there may be excessive air in the brake lines, the rear brake shoes may not be properly adjusted, or the brake hoses may be worn out.

    2

    Start your Astro in an empty parking lot; drive slowly and apply the brakes. If you hear shuddering and feel shaking from the rear brakes, the brake drums may be misaligned and will need to be realigned by a professional mechanic. Shuddering and shaking may also indicate damage to the wheel bearings, found most frequently in older vans that have rust and dirt caked inside the parking brake's housing. Residue, such as oil and dirt, can destroy the brake shoes if it accumulates over a long period of time.

    3

    Accelerate your Astro to about 30 miles per hour in an empty parking lot and press the brakes hard. If your Astro doesn't stop quickly and cleanly there may be a problem with the clearance between the brake shoe and drum. A sluggish braking response is usually due to worn out rear brake shoes, which will need to be replaced. New brake shoes often take a few miles to get properly broken in, so if you experience sluggish braking after replacing the rear brake shoes, give them some time before consulting a mechanic.

How Do I Troubleshoot a Triumph TR6 Backfiring Through the Carburetor?

How Do I Troubleshoot a Triumph TR6 Backfiring Through the Carburetor?

The Triumph TR6 was the pride of the British Leyland Motor Corporation with its in-line six-cylinder engine, disc brakes and advanced independent rear suspension. The sporty little TR6 package was rounded out with rack and pinion steering, bucket seats and sport instrumentation. When in tune, the TR6 is a powerful and fun car to drive. Problems with an engine backfire rob the car of its performance and fuel economy. Diagnosing and repairing a backfire is an easy task that lies well within the ability of the average weekend mechanic.

Instructions

    1

    Set the spark plug wires to the following firing order: 1-5-3-6-2-4 counterclockwise, with the 1 cylinder at the front of the engine.

    2

    Set the ignition timing. Connect one end of a 12-volt, 21-watt lamp to the coil's low tension terminal. Connect the other lamp lead to the battery's positive (+) terminal. Rotate the crankshaft pulley until the indicator hole on the pulley is exactly 3/8-inch to the left of the timing pointer. Turn the distributor until the lamp just comes on. Tighten the distributor and remove the timing lamp.

    3

    Check the vacuum retard on the distributor to ensure it is connected to the correct vacuum source. Check all other vacuum hoses for loose or cracked connections.

    4

    Adjust the ignition point gap to .015. Inspect the points to ensure they are not pitted or burned and that the spring is functioning correctly.

    5

    Adjust both ZS carburetors to set the idle speed at 900 RPM. Using the special synchronizing tool is the preferred method and the most accurate, but the adjustment can be done with a common vacuum gauge if a synchronizer is not available.

    6

    Adjust the valve clearance on all cylinders to .010-inch.

    7

    Check the wiring harness for loose connections or broken earth straps. Repair as needed.

Sabtu, 16 Februari 2013

After a Long Rain My Car Will Not Start

After a Long Rain My Car Will Not Start

The car's philosophy regarding water is that if it were meant to get submerged in water, it would have been born a submarine. The problem with a really long rain storm is that the water drops you see aren't the only water you get, and that the atmosphere winds up thick enough with liquid to seriously affect anything electrical. Once that water gets into your vehicle's system, there may be no end to the faults and malfunctions that may occur.

The Basic Problem

    Water -- but you probably already knew that. Almost anything is possible when you combine water and electronics; water conducts electricity, causing it to arc and cross circuits instead of coursing through the circuits that it should. And it doesn't take much; even extremely humid air can act as a conduit and cause sparks and electricity in circuit boards to jump to places where they shouldn't be.

Condensation

    Odds are good that your problem isn't so much one of liquid water leaking and splashing something in the engine bay; that would happen as much after a quick downpour as a two-day inundation. Long-running rains keep so much water in the air that the air saturates with as much vapor as it can hold at a given pressure and temperature. Allow that same air to get anyplace even slightly cooler than the outside air, and it's condensed into thick water droplets. This condensation tends to collect inside of distributor caps, electrical relays, computer control modules and even wiring harness plug ends.

Faulting the System

    First you'll need to isolate the system that is causing your fault: air, fuel, ignition or cranking. You can pretty much rule out air, since that will continue to go in as long as your filter isn't soaking-wet. Cranking system problems are just as obvious; if the engine turns over at normal speed when you turn the key, it's not a cranking system problem. That leaves fuel and ignition. The next step is to smell the exhaust as someone tries to crank the car. You should smell some fuel, but not enough to make your eyes water. If you smell nothing at all, then it's a fuel system issue. If sniffing the exhaust makes you want to forget about lunch, then it's likely an ignition system problem.

Fuel Stench -- Testing the Ignition System

    The simplest way to test for an ignition system fault is to go right to the plugs. Pull the plug wires off your plugs, insert an old plug into each wire end and hold the spark plug against your cylinder head with a pair of insulated pliers. The plug should pop with a blue-white spark. The alternative here is to connect a timing light to each of your plug wires and trigger it while someone cranks the engine. A consistent flash is good; no flash or erratic flashing indicates a fault. Look at and test the distributor, ignition module, ignition coil, all of the connections and your ignition system relay or relays (if so equipped).

No Smell -- Testing the Fuel System

    An electronic fuel injection system offers four basic opportunities for fault under these conditions. The fuel injectors may fail to fire, the fuel pump may fail to engage or the car's electric fuel pressure regulator (if so equipped) may cause pressure loss in the system. Fuel injectors are easy to diagnose: Simply put the tip of a long screwdriver on each injector and the handle of the screwdriver to your ear. You should hear a rapid clicking as the injector opens and closes. Next, test the fuel pressure. If you have none, then odds are that your fuel pump relay has a condensation problem.

Wild Cards and Electronics

    Wet computers and sensors can wreak all kinds of havoc upon your vehicle's fuel and ignition system, and computer housings aren't always tightly sealed. If you can't track the fault down to a bad relay, insulation chafed or stripped from wiring, loose connections or water build-up in the distributor or module, then you may be looking at a computer problem. The good news is that since it's not completely fried, you may be able to just pop the computer case open and re-seal it with silicone. The idle air control valve is the other wild card in this game: The IAC controls airflow into the motor at idle, so a fault in the IAC motor or control system could cause a fuel stench that you might otherwise mistake for an ignition problem.

Wholesale Auto Diagnostic Tools

Wholesale Auto Diagnostic Tools

You're driving your car and the engine light comes on. Your first thought is taking the vehicle to the mechanic and you sigh at all the trouble this heralds. But with auto diagnostic tools, you can often find the problem yourself. With today's improved on-board diagnostics, all you have to do is plug a diagnostic tool into the port near the center console, and your auto will send the information you need to the tool.

Professional Tools

    Professional auto diagnostic tools include enhanced interfaces for most brands of cars, or they come specialized for specific brands. You can buy them wholesale from most automobile manufacturers. These tools allow the mechanic to access hundreds of the cars systems, sensors and bi-directional controls. Professional tools also include subscriptions to the updates put out by the different manufacturers, and they are connected to live data to help the mechanic pinpoint the problem quickly and accurately. A good professional tool also performs system tests and shows trouble codes.

Stand-Alone Tools

    Stand-alone diagnostic tools are the more basic tools. They are available in many automotive stores and can be bought wholesale on the Internet. You can store a stand-alone tool in the car's glove compartment or in the trunk and have it on hand in case your engine light comes on. Just pull the car over anywhere or anytime and plug your diagnostic tool in. The code concerning the problem will light up on the screen. Then you can look up the code in the manual that comes with it. Some stand-alone tools will display the meaning of the codes on their screen. Once the problem is fixed, these tools can also turn off the "check engine" light.

Tools Using a Laptop

    In order to read the data stream and to understand what it means, these tools come with a USB cord, which you plug into a PC. They are more expensive but not much larger than the stand-alone tools, and they have print-out capabilities. Print out the problem codes and take them to your mechanic. This makes troubleshooting quicker and will save you some of the diagnostic charges. The data displayed on the screen can be played back to pinpoint the exact problem. These tools also work away from a laptop, but to get the most benefit from them, a PC is desirable.

How To Test PCM Circuits

How To Test PCM Circuits

Your powertrain control module is designed to indicate the existence of many different faults in your engine. Depending on your car's year, make and model, the PCM could be in several different places: in the engine compartment, in the panel along the passenger door, in the panel beneath the glove compartment or even under the carpet near one of the seats. To find out the specific fault, attach a code scanner to the car's code scanner and consult your manual to find out what the code means with respect to PCM functions.

Instructions

    1

    Insert the scanner into the port that connects to your car's data center. In many makes and models, you'll find this under the steering wheel or in the engine compartment on the driver's side. However, you'll need to consult your car's manual for the precise location, as it varies widely by make and model.

    2

    Turn your engine on and push "Read" or "Scan" (depending on the model) on the scanner. You may see just one code, or you may see several. Write all of them down. Then open the manual that came with your scanner to see what the codes mean. If your PCM circuits are working correctly, your codes should be accurate. However, if the scanner is giving you codes for components that are clearly working correctly, the PCM circuits could be at fault.

    3

    Unhook the cable running to the negative terminal on your battery. Touch a metal object while keeping your feet on the ground to ground yourself. Remove the PCM from the hardware holding in place, using your ratchet set. Take off the cover on the back of the PCM and look at the circuits. Any black stains on the board indicate circuits that have burned out. In this case, you need a new PCM.

Kamis, 14 Februari 2013

Why Does the "Service Four Wheel Drive" Light Come on in a 2005 Chevy Pickup Truck?

The four-wheel drive system in a 2005 Chevrolet pickup truck can be either a manual, lever-type control system or controlled by buttons on the dash. If the system uses buttons on the dash, it is operated with electronic controls. If the vehicle experiences a failure of part of the electronic system, the "service four wheel drive" indicator will be shown in the driver's information center at the bottom of the instrument panel.

Failed Encoder Motor

    The transfer case is shifted into different modes and ranges using an electric motor mounted to the transfer case, called an encoder motor. This motor provides a clockwise or counterclockwise motion that shifts the transfer case. It also provides an encoded feedback to the transmission control module to indicate a shift has been completed as requested. If the encoder motor indicates a shift has not been completed as intended, it may turn on the "service four wheel drive" indicator.

Failed Transfer Case Shift Switch

    The transfer case shift switch is a three- or four-button switch on the dash, which the driver uses to indicate the desired transfer case range or mode. The switch sends a signal to the transfer case control module, which then operates the encoder motor to complete the shift. If the switch is faulty, it can provide an incorrect signal to the TCCM, which may turn on the "service four wheel drive" indicator.

Failed Transfer Case Control Module

    The TCCM is the main microprocessor that operates the electronic four-wheel drive system. It is responsible for interpreting commands from the driver through the transfer case mode switch and operating the vehicle components to deliver the desired drive range or mode. If this module experiences a problem with its programming or internal circuits, it could turn on the "service four wheel drive" indicator.

Front Axle Actuator

    The front axle actuator is a motor with a gear drive that shifts the front axle from its freewheeling mode to engaged so that it may be driven by the transfer case front output shaft. When the motor fully engages the front axle, it sends a signal to the TCCM to indicate that engagement is complete. If the TCCM does not receive this signal, it will turn on the "service four wheel drive" indicator.

Wiring

    The "service four wheel drive" indicator may also be turned on because of defective wiring. If a wire is corroded or broken, the control circuit is not complete, and different components may not receive the required signals for correct operation. The broken wire may prevent the TCCM from receiving a signal confirming correct operation as well. If this is the case, the TCCM will indicate this fault with the "service four wheel drive" indicator.

What Would Cause Front Shaking When Accelerating on a 1999 Chevy Malibu?

The Malibu is one of Chevrolet's most storied offerings with a legacy stretching back to the marque's 1960s golden era. While a fine car overall, it's still no more perfect than any other vehicle out there, and 12-plus years and the concordant miles will have taken its toll on the chassis and engine. Shaking under light acceleration isn't a common problem, but it does happen from time to time.

Tire Problems

    Tire problems usually manifest with increases in speed, but can happen under acceleration under certain circumstances. There's usually a bit of play in a car's constant velocity joints, but under acceleration, the CV joint mechanism locks solidly together. Vibrations that normally wouldn't make it through the suspension instead transmits through the CV joint, and thus through the engine and engine mounts. If you bought your Malibu used, then it might have sat on a dealer lot or in someone's driveway for months without turning a wheel. Sitting for so long may have created a slight flat spot in the wheel, which would cause the car to vibrate slightly as though the wheel were out of balance.

Ignition Troubles

    Shuddering under acceleration might trace to the ignition system, or a malfunction thereof. Acceleration places more demands on a car's ignition system than simply idling or cruising, and the car may misfire if its ignition system isn't up to snuff. You may have one or more bad spark plugs or ignition coils, or you might have a crank position sensor on its way out. Crank position sensors will usually fail unilaterally, meaning that they'll cause a misfire regardless of what the engine's doing. However, a slightly malfunctioning crank sensor may lag behind the engine's actual rpm, not notifying the computer of a change in rpm until it's too late to do anything about it. So, the computer recognizes a fault and goes into open-loop programming until the crank sensor catches up. If this is the case, then you'll get a check engine light and a trouble code. Misfires can add to the front shaking during acceleration.

Chassis Problems

    Improper wheel alignment can cause any number of maladies in regards to handling, braking or acceleration. When you hit the gas, a certain amount of the car's weight shifts to the back, slightly lifting the front suspension and causing a change in geometry. Bad alignment settings, bent components and loose connectors may not manifest under normal circumstances, but may do so when the front end lifts during weight transfer. Bad rear wheel bearings can easily cause the symptoms described here. The same goes for CV joints; a bad or broken one can cause vibration under acceleration, especially in older cars.

Transmission Troubles

    A badly worn transmission, old transmission fluid or a malfunctioning torque converter can cause vibration under acceleration. Modern transmissions are precise instruments, and depend on an exact balance of fluid friction and viscosity modifiers to maintain the proper function. GM recommends flushing the transmission fluid at 50,000 miles, but you may need to do it more often if you regularly tow a trailer. If your transmission fluid looks brown or smells even slightly burnt, then do not flush it; just do a standard fluid change. Old fluid embeds into the transmission clutches, and its chemical properties are different enough from fresh fluid that the two won't mix right away. Do a flush on a car with extremely worn fluid and you'll do more than increase vibration -- you'll fry every clutch in the transmission.

Car Battery Fault Symptoms

A battery may or may not give out many discernible signs before it goes bad. There are symptoms that you can look for that would be related to identifying a faulty battery. The way to diagnose the problem decisively after spotting any battery-related symptoms is to allow a qualified mechanic to check the battery.

No Start

    When you slide your key in the ignition and twist, the engine will not crank at all. You may only hear a clicking noise, which slowly fades away to nothing. These symptoms could signal a battery that is dead or one that has bad cable or terminal connections. The battery needs to be checked by a mechanic in this situation to determine if it is indeed the culprit. These symptoms can also be caused by the starter, or the alternator or generator.

No Lights

    A symptom that the battery is faulty is to turn on the car lights. If the lights do not illuminate when you try turning them on, it is a dead battery. Also, watching the lights while you or someone else starts the car can allow you to spot symptoms of a faulty battery. If the lights are dim or go dim during this time, the battery has a low voltage. Other related symptoms of a dead battery are when the car is off and you turn the key forward in the ignition. With the key in this position, the car radio will not come on, and the windshield wipers will not work.

Slow Crank

    A symptom of a faulty battery is when your car starts, but it does so slowly. This symptom is called a slow crank, when you need to hold the key twisted in the ignition for an extended period of time while the engine slowly turns over and starts. The battery is not yet dead, but it is low on juice and will eventually not start the car.

Rabu, 13 Februari 2013

Signs and Symptoms of a Shorted Starter

Signs and Symptoms of a Shorted Starter

The starter is an electric motor that cranks your vehicle's engine when the key is turned in the ignition. This important component allows fuel to enter the cylinders to power your vehicle. A shorted starter can cause a variety of problems in a car; however, some of the symptoms and signs linked to a shorted starter can also relate to other mechanical issues. Ultimately, there are several things that can help you diagnose a shorted starter.

Clicking Sounds

    If your starter makes clicking or grinding sounds when you turn the key to crank the engine, it means you may have a shorted starter that has motor problems, or a gear is possibly stuck in the starter. The sounds originate from under your hood and are easy to hear because the engine won't turn over. However, if the engine does turn over but fails to start, or if you hear multiple clicks until the key is released, the problem may be a bad alternator, faulty battery connections or a choke that is defective or not adjusted properly.

Starting Issues

    A shorted starter can be the problem when your vehicle's engine fails to crank upon turning the key in the ignition. This happens because the shorted starter is unable to use the power originating from your car's battery, which is what the starter motor needs to turn the engine. If your vehicle's engine cranks so slowly that it isn't able to start, you may have a shorted starter. Keep in mind that a weak battery may also be the reason why your vehicle is not starting.

Dysfunctional Solenoid

    If you don't get any sound from your engine when trying to start it, but the lights and the windshield wipers are working, you may have a shorted starter with a faulty solenoid, which is the mechanical device on top of your starter motor's housing. Occasionally, this can be fixed by jiggling the key inside the ignition while turning it.

Smell

    A burnt smell or smoke coming from the starter motor under the hood is a sign of a shorted starter. This indicates there are electrical problems with the starter's wires and the connections within the starter motor. Any type of problem with the wires that connect to the starter solenoid can cause a short that ultimately creates a burnt smell or smoke.

Considerations

    Many auto parts stores test starters at no charge if they're removed and brought it. However, if you aren't sure how to remove the starter from your vehicle, it's best to let a professional handle this task. Ultimately, if you have one or more of the aforementioned signs or symptoms, you should take your car to a repair shop.

How to Tell If Power Steering Is Bad

How to Tell If Power Steering Is Bad

Broken or a leaking power steering pump typically causes the power steering system to fail. Driving a car without power steering can be difficult, and even dangerous, due to the way the vehicle handles when system is not properly operating. Cars manufactured during the last 20 to 30 years were never intended to operate without power steering and will be very hard to control. If the system has failed, it needs to be repaired to make driving safe.

Instructions

    1

    Check your power steering fluid as it may be the problem. Add fluid if needed.

    You can lose power steering if there is no fluid.

    2

    Check your serpentine belt. It powers the power steering pump and several other accessory components when the engine is running. If the belt is broken, chances are the alternator and other important systems also are not functioning. In this case, the problems is the power source for the power steering, not the actual system. Repairing the belt should fix the power steering.

    3

    Start the car. Gently turn the wheel to the right and then to the left. The wheel should move if the power steering is properly functioning. If this takes significant, the power steering system is probably not properly functioning.

    4

    Drive your car slowly and attempt to turn. The power steering should be fine if this is easy to do. If not, the system is not working.

How to Troubleshoot a Sentra

The Nissan Sentra is a compact car first introduced in 1982 as the Sunny. Depending on the year of the car, the Sentra may come with air conditioning, antilock brakes and power door locks and windows. As a Sentra owner, you may experience occasional problems with the car. You can troubleshoot basic problems with the Sentra with little auto repair experience. Basic troubleshooting can sometimes save you the expense of taking your Sentra into a mechanic or other auto repair specialist.

Instructions

    1

    Charge your battery if you are unable to start your Sentra. Check the battery by turning on either your windshield wipers or headlights. If neither turns on, then you need to charge your battery. Start your car using jumper cables connected to another car's battery. Connect the positive clips on the jumper cables to the positive posts on the Sentra's battery and the other car's battery. Connect the negative clips to the negative posts on the batteries. Attempt to start your car. When the Sentra starts, disconnect the jumper cables and allow the car to run for at least 10 to 15 minutes.

    2

    Check the brake fluid levels in the Sentra if the brakes feel spongy when depressed or if they go down to the floor. Raise the hood of the car and locate the brake's reservoir. The reservoir cap will be labeled "Brake." Clean the area around the cap and remove the cap. Check the amount of brake fluid in the reservoir against the fill line. If the fluid levels are low, add fluid. Use a funnel to avoid spilling brake fluid on other parts of the car. Replace the reservoir cap and lower the hood.

    3

    Turn the steering wheel and jiggle the key in the Sentra's ignition switch if you are unable to turn the key. Continue to turn the wheel left and right until you are able to turn the key. If you are still unable to turn the key after a few tries, try using a spare key to start the car. The key you normally use may be worn from repeated use.

    4

    Check the fuel levels in your Sentra if the car drives slowly or stalls. The fuel gauge on your dashboard will indicate whether or not you need to add fuel. Add fuel to the Sentra if necessary.