Kamis, 31 Desember 2009

Troubleshooting a 1996 Hyundai Sonata Mass Air Flow Sensor

Troubleshooting a 1996 Hyundai Sonata Mass Air Flow Sensor

The mass air flow (MAF) sensor in your 1996 Hyundai Sonata measures the amount of air flowing through the air cleaner assembly and into the engine. Overtime, though, dirt sticking on internal wires, circuitry malfunctions and failed internal components may render the MAF inoperative. So, finding the real source of the problem is important to avoid unnecessary replacements and expensive repairs. The MAF sensor in your Sonata is relatively accessible and you can troubleshoot it at home with a minimum of equipment and tools.

Instructions

    1

    Park your Sonata in a place with enough air ventilation. If you are inside your garage, open the door to the driveway. Start the engine and let idle for about 15 minutes so that it reaches operating temperature and then turn off the engine.

    2

    Open the hood and locate the MAF sensor. You will find the sensor mounted in the air cleaner assembly, between the air box, which contains the air filter, and the throttle body, which is the gate to the intake manifold, on top of the engine. You will see a four-prong electrical connector protruding from the sensor.

    3

    Inspect the wires visually in the harness connector leading to the sensor's connector, making sure they are in good condition and properly attached. Slightly pull on each of the four wires to make sure they are firmly attached.

    4

    Back probe the MAF sensor signal output and ground wires with your 10 megohm digital multimeter. The red wire with a blue stripe is the signal wire. The green wire with the white stripe, or third wire from the signal wire, is your ground. Connect the red meter probe to the signal wire and the black probe to the ground wire.

    5

    Set your meter to a low range on the Direct Voltage scale so that you can read up to 5 volts.

    6

    Ask an assistant to start the engine and to keep it at idle. Read off the value on your digital meter display. It should be between 0.7 and 1.1 volts.

    7

    Ask your assistant to rev up the engine up to 3000 rpm. Your meter display should read now between 1.3 and 2.0 volts. Turn off the engine. If the MAF sensor failed these tests, disconnect the ground (black) battery cable with a wrench and remove the sensor from the air cleaner assembly with a Phillips screwdriver without touching the mesh wires inside the sensor.

    8

    Place the sensor on a workbench and spray the wire mesh with mass air flow sensor cleaner, following the instructions on the product label, and reinstall the sensor in the air cleaner assembly.

    9

    Reconnect the ground (black) battery cable with a wrench and repeat steps 4 through 7. If your MAF sensor's readings are still out of specification, replace it.

What Is the Difference Between a Car Engine Burning Oil Vs. Leaking Oil?

What Is the Difference Between a Car Engine Burning Oil Vs. Leaking Oil?

Newer car engines rarely burn or leak oil. This is because the factory seals, O-rings, gaskets, bearings and components are new and undisturbed. With higher mileage and age, seals and gaskets break down, allowing oil seepage. Oil can leak past seals and gaskets, to enter the combustion chamber where it burns. Oil leaks not associated with the intake system or combustion chamber can show up as visible leaks on the ground's surface. The difference between leaking oil and combustion-burnt oil can be straightforward and uncomplicated. However, oil that enters the combustion chamber can be the direct result of internal leaks and a vehicle owner should know the difference.

Signs of External Oil Leaks

    The lower part of the engine provides the primary sources of external oil leaks, especially where pressure exists, or gaskets or seals must hold most of the engine oil. The rear main seal at the rear of the crankshaft will often leak oil, due to a faulty seal at the rear bearing location. The oil pan bolts, valve cover gasket, oil drain plug, oil filter and sensor, oil cooler and oil lines -- if so equipped -- will also show visible signs of leaking oil. Any puddle on the ground, or visible oil film or stream on the chassis or bottom of the engine, points to a failed seal, bearing, gasket or O-ring. If the visible marker on the oil dipstick constantly reports low readings, it can indicate a substantial external oil leak.

Signs of Oil Burning

    Oil burning originates in the combustion chamber of the engine. The most notable sign appears as a blue-white smoke exiting the exhaust pipe or pipes. Large clouds can appear just after engine warmup upon acceleration. Combustion-burnt oil can drip from the end of the exhaust pipe, or leak from exhaust pipe fittings and pipe clamps. Excessive oil burning can cause an engine miss or poor performance, unlike an external oil leak. Excessive oil inside the catalytic converter can cause clogging, leading to back-pressure, which can cause hard-starting and poor engine performance. Combustion-burnt oil will show low levels on the oil dipstick.

Causes for Oil Burning -- Valve Guides and Seals

    Engine valves seat inside valve guides, which are precisely drilled and honed sleeves. If the valve guides become worn, they let oil pass from the head into the combustion area and burn through the exhaust. Valve seals, which consist of small rubber O-rings, also keep oil from passing down the valve stem shaft, and if worn or broken, allow raw oil to seep into the combustion chamber. Oil-fouled plugs will appear wet or contain an oily sheen, and frequently cause the spark plug to misfire.

Causes for Oil Burning -- PCV Valve and Rings

    Positive crankcase ventilation, or PCV, consists of a valve component and tube or hose routing that recirculates engine bypass gases back into the intake. If the PCV valve clogs shut, or sticks periodically, it can cause high pressure in the engine crankcase. High crankcase pressure can cause excessive oil consumption, especially if the valve guides and seals are worn. Worn piston rings allow combustion gas pressure to enter the engine crankcase and cause the same high pressure. Oil diluted by gasoline, in the case of worn rings, will have a higher tendency to leak from worn O-rings, gaskets and seals.

Causes for Oil Burning -- Head Gaskets

    Depending upon the configuration of the vehicle's head gasket, an oil jacket in proximity to the edge of the cylinder can leak oil into the combustion chamber. If the head gasket is blown in this location, the oil can be sucked into the combustion chamber and burnt along with the fuel mixture. This will show as blue-white smoke exiting the exhaust pipe or pipes.

Summary

    Although a difference exists between a common oil leak and that of oil-burning, the difference is a fine line. Internal oil leaks, although different from external oil leaks, can be directly responsible for oil-burning, whereas an external oil leak will not show a decrease in engine performance, or show any visible signs of oil burning. However, they will both shows signs of oil loss with low readings on the oil dipstick.

OTC Evap System Tools

OTC Evap System Tools

OTC Tools specializes in diagnostic, service and maintenance tools for different industries, including the automotive industry. It is a subsidiary of SPX Corporation, which is headquartered in Charlotte, North Carolina, but ships its products worldwide. The evaporative emission control (EVAP) system on your vehicle captures and stores vapors created by too much fuel in your EVAP system. OTC Tools creates tools to help you diagnose and fix EVAP system issues. All of these tools are for industry professionals or mechanic shops.

Leak Tamer

    The Leak Tamer Plus EVAP helps you read EVAP diagnostic trouble codes (DTCs) on both domestic and foreign light trucks and vehicles. It uses the UltraTraceUV dye to find leaks in your system, and it meets original equipment manufacturer (OEM) test requirements. It was designed in collaboration with General Motors (GM), Ford Motor Company and Daimler Chrysler. The Leak Tamer Plus EVAP weighs 17 pounds, and its dimensions are 23 inches long by 18 inches wide by 9.5 inches high. It is compatible with all OTC LeakTamer accessories.

A/C System

    The A/C System Component Flusher helps you flush your EVAP system, lines and condensers. It uses a closed-circuit loop to move the solvent throughout your components. The solvent moves through a replaceable filter, before it returns to the storage vessel. The filter on this system is made of charcoal, to reduce odor. The liquid moves through your systems via a pulsing action. This system comes with adapters that fit 1/4-inch flare and 3/8-inch disconnect fittings.

LeakMaster

    LeakMaster Evaporative Emissions System Tester helps you locate leaks within your EVAP system, and you also can use this system to find leaks in vacuums, the dash, exhaust and the crankcase. It also will locate air, water and oil leaks. This tool is compatible with different model foreign and domestic vehicles. It comes with a full charge of UV solution that you can refill when you run out.

Portable Inspection

    The Portable Inspection Enclosure provides you with a dark area when inspecting your engine, and it allows you to run tests on your EVAP system. It comes with UV dyes to locate problems with your engine oil, coolant, air conditioning system and transmission. It runs crossfire and ignition traces to determine if something is wrong with your spark plugs. The Portable Inspection Enclosure also provides you with a safe place to work in inclement weather.

Rabu, 30 Desember 2009

How to Make a Car Air Conditioner Cooler

How to Make a Car Air Conditioner Cooler

If you are looking to make your car's air conditioning system cooler, then chances are it is emitting warmer air than normal. If this is the case, it is more than likely that your car is running low on coolant. Recharging your car's refrigeration chemicals should make your air conditioner as cool as it can be.

Instructions

    1

    Purchase a can of refrigerant from a local automotive supply store. Buy the appropriate type for your vehicle by reading the instructions.

    2

    Locate the service fittings on your vehicle. There are two: the low side fitting and the high side fitting. The low side fitting can be located under the hose that goes from the accumulator to the compressor. The high side fitting is on the hose that goes from the compressor to the condenser.

    3

    Connect the recharge hose to the can of refrigerant and turn the valve on the top of the can to puncture the top of the can, allowing the coolant to escape.

    4

    Disconnect the low side fitting and connect the can of refrigerant where it was. Turn the valve on the can to slowly release refrigerant into the AC hose. Most cans of refrigerant come with a gauge on the side to let you know when the coolant is at a desired level.

    5

    Remove the can and reconnect the low side fitting. Turn on your air conditioning.

How to Troubleshoot a 1977 Ford Duraspark ll Ignition System

How to Troubleshoot a 1977 Ford Duraspark ll Ignition System

The Duraspark II ignition system debuted in 1976 with the intent to make substantial increases in secondary voltage and extend system maintenance intervals. Spark plug gaps were widened to take advantage of the heightened current and to prolong spark plug life. Special testers were devised at the time, but the troubleshooting capabilities of such analyzers are easily duplicated with an accurate volt-ohmmeter. Knowing what values to look for in certain circuits is often the only specific information needed for effective system diagnosis.

Instructions

    1

    Test the car battery state of charge and clean the cable terminals if necessary. Charge the battery if stored voltage is below 12.5 volts. Replace the battery if voltage drops below 9 volts while cranking the engine. Ensure battery and cable conditions are good before evaluating any subsequent voltage readings.

    2

    Measure the voltage to the ignition coil positive terminal while cranking the engine. Repair the circuit from the ignition switch, or replace the switch if the reading is not the same as battery cranking voltage. Turn off the power to the ignition system and measure the resistance of the ignition coil primary terminals. Replace the coil if this reading exceeds 3 ohms.

    3

    Test the resistance of the distributor pickup coil with the ignition switch remaining in the "Off" position. Unplug the distributor wire harness from the black plastic connector. Measure the resistance between the two parallel prongs of the distributor harness. Replace the pickup coil if the resistance is more than 850 ohms or less than this value by 60 ohms or more. Measure the resistance between both parallel prongs and the single perpendicular prong, one at a time. Replace the pickup coil if any value below 70,000 ohms is displayed.

    4

    Restore the connection at the distributor harness. Measure the cranking voltage to the ignition module, or "brain-box". Probe the white wire leading into the module while cranking the engine. Inspect the circuit from the starter solenoid "S" terminal, if the voltage is weak or missing entirely. Replace the solenoid if no faults are found in the circuit.

    5

    Probe the red wire leading to the ignition module with the ignition switch in the "Run" position to ensure a proper voltage signal. Repair the circuit if readings are less than battery voltage. Test the resistance of the ground circuit by probing the black wire at the module and distributor. repair this circuit if readings exceed 0.3 ohms. Replace the module if symptoms persist without any other ignition system causes.

Selasa, 29 Desember 2009

How to Diagnose a Problem With Windshield Wipers in a Car

How to Diagnose a Problem With Windshield Wipers in a Car

Vehicle windshield wipers serve a very important function, relating to the visibility and safety of the driver and occupants. Windshield wiper systems primarily consist of wiper blades, wiper arms, a linkage system, motor and sometimes a washer pump and fluid reservoir. A vehicle owner will need to use the process of elimination to find the exact cause of windshield wiper malfunction. This can be done by using some simple diagnostic steps and a few tools.

Instructions

    1

    Place the vehicle in "Neutral" for a standard transmission or "Park" for an automatic. Set the emergency brake and raise the hood. Locate your main fuse box and look for the windshield wiper fuse and-or relay. The fuse will be a type of glass tube or a spade design. Visually inspect the fuse to see if the filament inside either type is internally disconnected or blackened. Replace the blown fuse. Pull the relay out and swap it with another relay of the same pin design and voltage. Turn the windshield wiper on and see if it functions. If it does, the fuse or relay was the problem.

    2

    Turn the windshield wiper on; you might also have to turn the ignition key to the "On" position. Look and listen for windshield motor movement and sound. If you see no movement and hear no sound, turn the windshield motor switch off. If the wiper motor is concealed under the top outside vent panel, use a screwdriver to remove the panel. If your windshield washer motor operates by a vacuum system, check the vacuum hose for cracks and loose connections from its source to the windshield motor. Repair the vacuum hose or tighten the connection.

    3

    Examine the wiper rod linkages. You will see a main driving arm and two wiper rod arms, supported by pivots. The linkage rods are connected by spacers and cotter pins, or with small nuts. Make certain the pins or nuts have not come loose or fallen off the arms. The arms should not be bent or disfigured. Look for twigs or small stones wedged between the linkage arms and remove them. Move the linkage arms manually to see if they cycle. Spray some white grease on all the linkage arm connections and pivot points.

    4

    Inspect the windshield wiper motor drive gear where it connects with the main linkage rod. The gear or sleeve should not be broken or misaligned. Feel the mesh of the mating gears for tautness. Tighten the wiper motor mount bolts with a socket and ratchet, or use a screwdriver, if it is equipped with screw fasteners. If the windshield wiper motor has a ground strap, unscrew the ground strap with a screwdriver and clean the connection with a piece of sandpaper, then reconnect it and tighten it.

    5

    Inspect the connector wire to the windshield wiper motor for a clean and tight fit. Turn on the ignition key and the windshield wiper switch. Clamp a lead from a test light to ground and stab the hot wire on the wiper motor with the test light probe. If you have voltage, the problem lies with a defective wiper motor. Check your windshield washer pump motor in the same fashion by having an assistant activate the pump button with the key and switch on. Ground the test light lead and stab the test light probe into the hot washer pump wire -- voltage at the washer pump motor means the small motor is not functioning.

    6

    Inspect the condition of the wipers blades if they fail to make a clean pass over the windshield and leave streaks. Replace them, if necessary, by unclasping the old blades and snapping the new ones on in the frame guides.

Why Would a Car's Battery Lose Power When the Car Is Idle?

If your battery's going dead at idle, then it may be trying to tell you something about your car. Batteries are energy storage banks, subject to the whims of the electrical system and often suffering from the faults of other components. So, if your battery tells you something that you don't want to hear, don't just shoot the messenger. Diagnose the root fault and fix it before you go throwing expensive new parts at an unrelated problem.

Charging System Basics

    An alternator is basically an alternating current motor in reverse, converting kinetic energy (via the crankshaft) into electrical energy via a set of magnets and coils. A set of diodes in the alternator convert its AC current to a direct current that the battery can use. The higher the power demand, the more diodes come online to supply it. Cars don't draw most of their power right from the alternator; rather, the alternator charges the car's battery, and the battery acts as a sort of surge tank for the electrical system. Only the car's ignition coil draws power directly from the alternator, and even that isn't true in many cases.

A Failed Alternator

    An alternator, as a mechanism, won't necessarily fail, but it will tend to exhibit a predictable set of symptoms. The diodes inside an alternator are like one-way gates for electrical current; when the diodes get hot enough, they'll burn out and force current to flow through the remaining diodes. That excess current will eventually overheat the other diodes, causing them to fail one by one. Each diode that fails reduces the amount of charge that the alternator can deliver, particularly at idle speeds. If the engine's ignition system and accessories draw more power from the battery than the alternator can replace, then the battery will go dead, as will the engine soon afterward.

A Failed Battery

    Imagine your battery as a rectangular bucket divided into twelve chambers, each holding a certain amount of water. Now, imagine that you drill a single, very small hole through the walls dividing those chambers so that water from one can slowly flow into another. Next, drill a large hole into the bottom of one chamber and watch what happens. The water from that single chamber will quickly empty, and water from the adjacent chambers will trickle in to fill it. That water is electricity, and those chambers are your battery's cells. If one cell fails, the others will constantly try to "refill" it with electricity. The effect is that same as that that of a failed alternator, particularly since constant inter-cell electrical flow will eventually destroy other adjacent cells.

Excessive Draw

    There are two basic types of circuit malfunctions: an "open," or incomplete circuit, and a "short" circuit. A short circuit is what happens when something connects a power source's lines before they reach the intended accessory; this will cause an excessive draw that your alternator can't keep up with. Shorts come in two varieties -- either external shorts, occurring somewhere in the car's electrical system, or internal shorts, occurring in the battery itself. Often, a "dead" cell is actually an internal short. High-powered, aftermarket devices such as electric fuel pumps, electric cooling fans, auxiliary lights and ground-thumping stereos may overwhelm older-model alternators, which don't typically deliver the kind of amperage that modern ones do.

Senin, 28 Desember 2009

How to Troubleshoot Engine Problems on a 2000 BMW 3-Series

How to Troubleshoot Engine Problems on a 2000 BMW 3-Series

The easiest way to troubleshoot a 2000 BMW 3-series engine involves the vehicle's second generation On-Board Diagnostic system. Due to Environmental Protection Agency rules, all cars and light trucks manufactured and sold in the United States must use standardized coding. Essentially, 3-series vehicles contain a powertrain control module; this computer monitors the engine and records instances of malfunction. You can access this record with an ODB-II code reader. This makes for a quicker diagnosis than investigating an engine yourself, by trial and error.

Instructions

    1

    Open the 3-Series vehicle's driver's side door. Get behind the wheel and place your key into the BMW's ignition. Leave the key unturned at this moment.

    2

    Feel beneath the dashboard for the BMW's data link connector. The DLC is an outlet, and it serves as your entry-point into the BMW's PCM. For a 2000 3-Series, the DLC is on the left of the steering column, next to the left kick panel. You will have to remove a cover to get at the 16-pin receiving DLC outlet.

    3

    Connect your code reader's diagnostic cable to the DLC outlet. Turn the key in the BMW's ignition to the "On" designation. Depending on the type and brand of your OBD-II code reader, you may have the crank the engine as well.

    4

    Look at your code reader's display. If your device did not immediately retrieve OBD-II codes, you will have to punch in a "scan" command. Since code readers are all different, look up the instructions in your reader's manual.

    5

    Read through the codes on your reader's display. At this moment, you only need to pay attention to the OBD-II codes that begin with the letter "P." Those are powertrain codes (P-codes), which covers both the engine and the fueling system. Ignore codes that start with "C," "B," or "U."

    6

    Check the status of each code. Your code reader will have either an icon or some other indicator for "Trouble" and "pending" codes. Trouble codes have happened enough to trigger your check engine light. Pending codes have not happened as frequently. They could be anomalies, or they could be problems that the PCM may later, if the exact problem persists, reclassify as "trouble."

    7

    Copy the codes out onto a separate sheet of paper. At this point, you are making a list of priorities. Place "trouble" codes at the top of this list. Place "pending" codes at the bottom.

    8

    Look up the definitions and explanation for each P-code you copied from your reader. Start with the generic codes. These will be listed in your operator's manual. Then, you well need to find BMW's special, supplemental OBD-II codes. You will find these either in a Chilton repair manual, or you will find them for free on the Internet. Copy the definitions next to their corresponding P-codes.

    9

    Turn the electrical system and/or the engine off. Disconnect your scanner from the BMW's DLC outlet. Prop open the BMW's hood, and investigate the engine according to your list. Troubleshoot not only the specific component named in the coding description, but also the area around it. For example, P0165 means "O2 Sensor Circuit Slow Response (Bank 2 Sensor 3)." Look not only for that exact problem; double check the entire oxygen sensor.

How to Troubleshoot an Infiniti Problem

Owned by Nissan Motor Company, the Infiniti car brand features some of Nissan's more luxury-oriented vehicles, such as the popular G-series coupes and sedans. Though Nissan and Infiniti are generally known for their long-term reliability, it's normal for small problems to develop on your Infiniti over time, especially on models with high-mileage. The most common issue with Infiniti vehicles is the development of various rattles, especially from interior components. Other common issues can be easily troubleshooted with careful inspection.

Instructions

    1

    Listen for the source location of any interior rattling noises while driving, as they are most likely to occur when going over bumps or uneven surfaces. Using the heel of your hand to lightly bang on the dash and various other plastic interior components is a good way to reproduce rattles. Most interior components are secured with plastic clip fasteners, though larger components may also be secured by Phillips-head screws. Ensure all plastic clips are secured, and tighten any interior screws to rid your Infiniti of unsoundly interior rattles.

    2

    Listen for exhaust rattling when accelerating your Infiniti. Since the exhaust system is exposed to the elements, it is common to incur exhaust damage over time from various road debris and general wear. Common sources for exhaust rattles are loose heat shields, which are bolted overtop of the exhaust piping at various points under the vehicle. Damaged exhaust hangers can also lead to exhaust system rattles. Tighten any loose bolts securing the exhaust heat shields and replace any portions of the exhaust with cracks or damaged hangers.

    3

    Ensure all of the flange bolts securing the various segments of exhaust piping are secure. On some Infiniti vehicles, this may require raising the vehicle with a floor jack and jack stands to access the exhaust bolts. Loose exhaust flange bolts can lead to exhaust leaks, which will create an unsoundly exhaust noise, as well as rob your Infiniti of performance. Exhaust bolts coming loose over time are common due to the extreme engine heat and vibration the exhaust system is subjected to under normal driving. Tighten any loose exhaust flange bolts throughout the exhaust system.

    4

    Remove the plastic air box cover in the engine bay, secured by metal clips. Inspect the air filter inside to ensure it is free of damage or collected debris. Replace the air filter if it is worn out to retain your Infiniti's horsepower and fuel mileage performance. Inspect any rubber lines throughout the engine bay, such as vacuum and radiator lines. Rubber lines are prone to breaking down under the extreme heat generated by the engine, leading to various performance and emissions issues. Replace any faulty lines with factory or universal units, available from most automotive parts retailers.

Minggu, 27 Desember 2009

The Headlights Won't Work on a 1998 Mercury

If the headlights on your 1998 Mercury aren't working, one of four possible things could have gone wrong. The bulb may have burned out, the wiring harness bringing power to the bulb may not be functioning, the fuse may have blown or the headlight switch may be faulty. Each of these possibilities can be diagnosed in a straightforward and simple procedure that determines why your headlights aren't working and which part needs to be fixed or replaced.

Instructions

    1

    Turn on your low- and high-beam headlights. Step outside the car to see whether any of these headlights are working. Replace a non-functioning headlight bulb if all but that one are working.

    2

    Turn off the vehicle and prop open the hood.

    3

    Open the headlight fuse box and check to see if any of the fuses are blown. Check the diagram on the inner cover of the fuse box for the location of the fuses controlling the headlights that are not working. With two fingers, pull those fuses out of their slots and inspect whether there is any discoloration or disconnection inside the fuse. Replace any fuses that are blown.

    4

    Attach the positive lead of the voltmeter to the positive terminal on the car battery. Disconnect the wiring harness from the rear of the non-functioning headlight. Connect the negative lead of the voltmeter to the leads on the wiring harness to check that power is coming through to the wiring harness. Replace the wiring harness if the voltmeter shows at or near "0" on the power lead from the wiring harness. Continue to Step 5 if your headlights are still not working.

    5

    Sit in the driver's side seat and remove the steering column bezel to gain access to the headlight switch. Carefully remove the wiring harness from the headlight switch and check the leads on this harness just as you did with the harness on the headlight assembly. Replace as needed. Replace the headlight switch itself if power is coming through the harness and none of the headlights are functioning.

Honda Civic 88 Sometimes Won't Start

Honda Civic 88 Sometimes Won't Start

You sit behind the steering wheel of your 1988 Honda Civic with a full day's plans mapped out in your head. You turn the key and the car won't start; again. There are a few simple tests, as well as few tricks, to perform in order to discover why the Honda does not always start when you want it to.

Instructions

    1

    Ensure that the key is inserted completely into the ignition and turned all the way forward. A key turned to the 'On' position will start all the electrical accessories of the vehicle but will not start the car.

    2

    Note the position of the transmission. If the vehicle is automatic the shifter must be in the park position for the car to start. Ensure that a manual stick shift is placed in neutral.

    3

    Depress the brake pedal firmly while turning the key. The car will not start without it. Troubleshoot the brake pedal sensor by pumping the brake while turning the ignition. If the engine starts and stops with the pumps the brake sensor may be compromised.

    4

    Depress the clutch pedal, if manual, fully while starting the car. Pump the pedal while turning the ignition to see if the clutch pedal sensor is faulty. The engine will spark and stop intermittently if the sensor is bad.

    5

    Turn the key to the 'On' position and test the electrical accessories for a dead battery. If the radio, interior lights and headlights do not all function concurrently at full capacity than the battery must be checked.

    6

    Open the hood of the vehicle and check the integrity of the battery terminals. Corrosion around the terminals while stop electricity from conducting. Clean the terminals with a wire brush, or something as simple as your keys, until shiny metal is contacting shiny metal.

    7

    Follow the negative battery terminal cable through the engine compartment to the starter motor. Check all wires feeding into and out of the starter for damage or corrosion. Spraying WD-40 on any suspected bad connections will help temporarily restore the connection.

    8

    Locate the distributor on the front of the camshaft. Ensure all wires coming into and out of the distributor are connected tightly and there is no damage or corrosion. Firmly press the wires into the distributor and spark plug heads.

    9

    Notice if the car is parked at an incline. A bad fuel pump or clogged fuel lines will not supply enough gasoline if the engine is higher than the gas tank. Replace the fuel pump if the vehicle does not start on an incline.

Sabtu, 26 Desember 2009

How to Put a 1990 Toyota Pickup Into Diagnostic Mode

How to Put a 1990 Toyota Pickup Into Diagnostic Mode

On-Board Diagnostics became standardized in 1996 across all makes and models of motor vehicles. Prior to 1996, manufacturers had their own separate distinctive systems. Collectively, this first generation of diagnostic systems is now referred to OBD-I. The second generation after 1996 is now called OBD-II. While there are scanners for these older diagnostic systems, they are not required. The cars and trucks themselves can be put into a self-testing mode, and Toyota Pickups are no different. So long as you have a length of jumper wire, you can make the pickup relay trouble codes via a flashing check engine light.

Instructions

    1

    Pop the Toyota's hood and look in the far right corner of the engine compartment. You find two tube-like connectors with rubber caps.

    2

    Remove the rubber caps and connect the two ports with jumper wire.

    3

    Place you key into the Toyota's ignition and turn. Leave the engine off. You just want the electrical system turned on.

    4

    Count how many times the check engine light flashes. Toyota OBD-I codes are two digit numbers. There will be a slight pause between numbers. For example, code 21 will flash twice followed by a short pause and one more flash. There will be a two second pause to signal the relaying of separate trouble code.

    5

    Look up the codes online for definitions. There are websites archiving older OBD-I coding systems and their definitions. They can be found in the references section.

Jumat, 25 Desember 2009

How to Diagnose Auto Electrical Problems

How to Diagnose Auto Electrical Problems

If your vehicle is having trouble starting, you could be experiencing an issue with the electrical system. Take the time to go over a few basic tests and you may be able to determine what the issue is without having to hire a mechanic. Diagnosing the issue yourself can also save time, as many small repairs can be fixed quickly with little effort.

Instructions

    1

    Open the hood of your car and take a good look at the battery, including the cables connected to it and the terminal posts. This visual test can answer quite a few questions. Look closely for corrosion from the battery and use baking soda to remove it by pouring the soda over the corrosion. Jiggle the battery cables and tighten them with a battery terminal wrench if they are loose at all. Clean the battery posts with a battery post cleaner to ensure a solid connection.

    2

    Test the battery voltage and terminal connections on the car while the engine is idling. Use a voltmeter and look for a reading between 13.8 and 15 volts. If the reading drops between 12.8 to 13 volts, your alternator may be malfunctioning.

    3

    Attempt to start the car and listen for a whirring sound followed by a clicking sound. If you hear these sounds, it is possible that your car's starter motor is failing. Remove the air filter to gain access to the starter. Tap the back of the starter gently with a hammer to try to engage the fly wheel. If this fails, contact a mechanic about a replacement starter motor.

Kamis, 24 Desember 2009

How to Troubleshoot the Fuel Pump in a 2002 Nissan Sentra

How to Troubleshoot the Fuel Pump in a 2002 Nissan Sentra

The car won't start, or it acts like it is trying to stall when being driven. Chances are, you've replaced the fuel filter, given the engine a tune-up, and checked the starter, alternator and battery. Maybe it's the fuel pump. Fuel pumps are expensive, so don't buy one unless it is absolutely necessary. Take the time to troubleshoot the system. After all, spending money on a fuel pump not knowing for sure that the fuel pump is bad is not only a waste of money but a waste of time as well.

Instructions

    1

    Remove the gas cap.

    2

    Turn the ignition switch to the On position, but do not start the vehicle. The fuel pump makes a whirring noise for a few seconds when it is working. Have someone assist with this step if necessary.

    3

    Check the fuel pump fuse if no noise is heard. (The fuel pump fuse is located on the lower dash panel near the hood release panel. It is the number 17 fuse.)

    4

    Replace the fuse if it is blown. (A break or possible burn is noticeable.)

    5

    Follow the wiring from the fuse panel to the fuel pump if the fuse blows again. Look for open, loose, cut or burnt wiring and replace the harness if necessary.

    6

    Check the fuel pump relay if the fuse is not blown. The relay is mounted in the relay box under the hood. Connect a ground to terminal 1 and battery voltage terminal 2. You'll hear a click if there is voltage.

    7

    Remove the fuel pump relays and check for battery voltage to the fuel pump, using a voltmeter.

    8

    Trace the wiring from the circuit for open, cut, loose or burnt wiring if no voltage is present. If voltage is present and the relays are good, replace the relays.

    9

    Remove the rear seat. Use the voltmeter to check for power at the fuel pump harness connector. If no power is present, trace the wiring from the relay circuit to the fuel pump harness. Check for damaged wires.

    10

    Replace the fuel pump if power is reaching the fuel pump and the relays are good.

Minggu, 20 Desember 2009

How to Check the Ignition Coil on a Late Model Auto

How to Check the Ignition Coil on a Late Model Auto

Gasoline-powered automobiles rely on ignition coils to drive the spark plug to ignite the air-fuel mixture. Over the years, the principle has remained the same, but the design of these ignition coils has changed. The traditional round can style of ignition coil has been replaced with a smaller, more-compact unit. Just like the predecessor, the ignition coil on late model autos may need to be replaced with a fresh coil. Testing the ignition coil will help make that determination.

Instructions

    1

    Prepare to test the ignition coil. Turn on the digital multimeter and review the service manual for resistance specifications for your vehicle's ignition coil. Also, refer to the service manual to locate the poles for your specific ignition coil.

    2

    Check the primary coil. Touch one probe lead to one of the marked poles and the other lead on the other pole. Compare the resistance reading you obtain with the specifications in the service manual.

    3

    Test the secondary coil. Following the same procedure for the primary coil, connect the probe leads to the appropriate poles and compare the measured resistance with the accepted range of values.

    4

    Determine whether the coil is usable. If the coil resistances are both within the acceptable range, the ignition coil is usable. However, if it fails either test, it should be replaced.

Sabtu, 19 Desember 2009

Faulty Ignition Coil Symptoms

Faulty Ignition Coil Symptoms

An ignition coil manages the voltage sent to the engine's spark plugs during start-up. The component is in effect a signal booster, amplifying a 12-volt starter charge into as much as 40,000 volts according to AA1 Car. When this component fails it can cause performance problems for the vehicle's engine, including diminished acceleration. A bad ignition coil should be replaced immediately to avoid being stranded on the side of the road.

Engine Misfire

    Faulty ignition coils affect every engine cylinder causing it to misfire badly, according to automotive repair website AA1 Car. This condition occurs most often during acceleration when the engine is under load. Misfires may jump from cylinder to cylinder causing stall outs and all but cripple engine operation. In engines with a distributor-less ignition system, a single faulty ignition coil may only cause misfiring of one or two engine cylinders. These systems are easier to diagnose than distributor-based ignition systems.

Check Engine Light and Rough Running

    Your vehicle may experience rough running conditions such as sluggish engine performance caused by a faulty ignition coil. This is commonly referred to as a lack of "get up and go." The engine may not misfire but instead seem as though it requires more gas to get up to speed. According to AA1 Car, vehicles using engines made after 1996 have on-board computer systems which detect fault codes triggered by failing ignition coils. This may cause the computer to illuminate your vehicle's yellow "check engine" light located on your dashboard.

No-Start Condition and Engine Damage

    A faulty ignition coil significantly affects the voltage traveling to the engine. As a result, your engine may not have significant power to complete the ignition process resulting in a no-start condition. Repeated starting attempts could cause damage to the vehicle's spark plugs as these components receive a charge each time the ignition coil attempts to boost the voltage signal from the starter.

How to Diagnose Electrical Headlight Problems on Your Car

If the headlights on your car are not working, one of four major electrical components may have failed: the headlight bulbs themselves, the wiring harness bringing power to the headlights, the fuses that operate on the circuit to protect it from power surges, or the headlight switch, which allows the driver to change between low and high beams. Any one of these components may be the source of your headlight problems. Diagnosing the issue is a straightforward process.

Instructions

    1

    Turn on your headlights. Replace whichever headlight bulbs do not turn on. Although the process for replacing a headlight bulb varies by make and model of vehicle, in general, to remove the bulb: disconnect the wiring harness from the rear of the headlight assembly, disengage the retaining clip and pull out the bulb. Insert the replacement bulb, secure it with the retaining clip, and plug back in the wiring harness. Test the headlights again. Continue to the next step if any do not turn on.

    2

    Open the engine compartment fuse box. Pull the fuse that operates on the non-functioning headlight circuit. Inspect the fuse for discoloration. Replace as needed. Turn the headlights on again. Continue to the next step if any still do not turn on.

    3

    Connect the negative lead of the voltmeter to the negative terminal on the car battery. Connect the positive lead of the voltmeter to the positive lead of the wiring harness. The positive lead has power coming through it and is usually the red wire. Verify that power is coming through the wiring harness. Replace it if no power is coming through. Turn the headlights on again. Continue to the next step if they still do not turn on.

    4

    Disconnect the negative battery cable from the car battery. Remove the bezel around the steering column of the steering wheel. Unplug the wiring block from the back of the headlight switch. Check whether the contacts on the wiring block or headlight switch are discolored. Clean them gently with a pencil eraser. Plug back in and turn the headlights on again. If they still do not work, you may need to replace the headlight switch.

Kamis, 17 Desember 2009

How to Troubleshoot a Lincoln Ignition Switch

How to Troubleshoot a Lincoln Ignition Switch

Engine starting, electrical and accessory circuits, the steering wheel and the gearshift lock are all controlled by the ignition switch on Ford Lincoln vehicles. The ignition switch is operated using a key, which provides a measure of security by preventing the car from being started and driven away by an unauthorized person. Problems with the ignition switch can be related to the switch itself, the position of the key, or starting with the computer-assisted cranking system. These various issues can be corrected through troubleshooting.

Instructions

    1

    Insert the key in the ignition lock and turn it clockwise through the four positions if the ignition switch doesn't seem to be working right. The first position is the "Off" position and is the starting position when you inserted the key. Moving the key to the second position will activate the accessory circuit, which will allow devices like the radio to function. Moving the key to the next click is the "On" position. This position activates all of the electrical circuits. Moving the key to the fourth position starts the engine.

    2

    Move the gearshift to the "P" or "Park" position if the engine won't crank when you turn the key to the fourth position on the ignition switch.

    3

    Turn off all lights and accessories if the lights dim and the engine cranks slowly when you turn the key to the fourth position. This suggests a problem with a low battery charge and is rather common on older cars. It does not indicate a problem with the switch. Have the battery replaced at the earliest opportunity.off all lights and accessories if the lights dim and the engine cranks slowly when you turn the key to the fourth position. This suggests a problem with a low battery charge and is rather common on older cars. It does not indicate with the switch. Have the battery replaced at the earliest opportunity.

    4

    Release the key when the engine begins to crank and allow it to spring back from the fourth position to the third position ("On"). The cranking is computer-assisted and can continue for up to 10 seconds after you release the key. This is normal.

Problems a TP Sensor Can Give

The throttle position sensor is one of your engine's most vital information-gathering apparatuses, and possibly the most vital depending on what kind of redundancies it uses. The TPS tells the computer how far you've opened the throttle blades, a bit of information that it can't extrapolate using any other sensor onboard. If your car starts to surge and the check engine light dings, then that may well be the sound of those iron bells tolling for your unfortunate throttle position sensor.

Idle Surging

    A bad throttle position sensor will often first manifest as a slight surge -- random rise and fall -- in idle. Idle is when the engine is at its most sensitive, when airflow going into the engine measures in cubic centimeters instead of cubic inches. At this stage, a bad TPS may mimic the symptoms of a bad idle air control valve.

Hesitation During Acceleration

    The engine's next most sensitive point is during hard acceleration, when everything has to work together perfectly in order to get the engine to its maximum power potential. A bad TPS will send a false signal to the computer, informing it that you're opening and closing the throttle. The computer will adjust fuel injector and ignition timing to compensate, only to dial it back once the oxygen sensors notice the discrepancy.

Surge in Speed

    This particular phenomenon can be a bit scary, but not every vehicle will do it. Under normal conditions, the car's computer opens the idle air control valve to meter air around the throttle blade at idle and then closes the valve once the throttle blades have opened past a certain point. This gives the computer some leeway in terms of increasing airflow, which it may do if the oxygen sensors detect a rich condition. The result is a bout of unintended acceleration or brief surge in speed.

Bucking and Jerking

    Once the TPS reaches its near-failure point, it'll go from sending a smooth waveform signal to the computer to sending it an on-off signal like a light switch. The computer responds as quickly as it can, likely under the impression that you've completely lost your mind. If the TPS doesn't send a constant on-off signal, then it may just randomly shoot between full on and full off. The computer is at a loss, and a more severe version of surging manifests as heavy jerking and bucking.

Stalling

    Buy some pretty flowers and call the pallbearer, for your TPS has officially died. Stalling is the inevitable end progression from idle surging to drive surging to bucking, and there's no going back from here. If you've experienced all of the prior symptoms -- or possibly even if you haven't -- and the car begins to randomly die at idle or during cruise, then it's time to install a new TPS to your throttle body.

A '96 Dodge Caravan That Cranks but Won't Start

A '96 Dodge Caravan That Cranks but Won't Start

The 1996 Caravan was offered with two motor options, an in-line four cylinder and a more powerful V6. In either configuration there are a few simple things to check when the vehicle cranks but won't start. Every vehicle needs five things to start: fuel, air, spark, timing, and compression. Determining which of these is missing will determine the next steps in fixing your Dodge Caravan.

Instructions

    1

    Check for fuel. Ensure that your gas gauge is working, and that your van actually has fuel. Then check fuel pressure. Attach the fuel pressure tester to the fitting on the fuel injector rail. Have an assistant crank the engine, or use a remote engine starter, then check the reading on the pressure gauge. Pressure should be 49 - 55 psi. If you do not have proper fuel pressure investigate the fuel filter, fuel pressure regulator, and the fuel pump. Fuel pressure regulator problems are the most common on this model.

    2

    Check for spark. Attach the timing light to the number one spark plug wire, and turn the engine over. With the timing light trigger depressed, the light should flash. If it does not , the engine is not getting spark, and ignition components need to be tested. Start with the ignition control module as this is the most common failure on the Dodge Caravan. Remove the module and have it tested at your local auto parts store. If the module is good, test the coil and the crank position sensor. Replace if necessary. If there is still no spark, remove the distributor cap, and ensure that the distributor rotor is turning. If it is not, the most likely cause is a broken timing belt.

    3

    Check for timing. If you have spark, but the vehicle will still not start, leave the timing light clamp around the number one spark plug wire, and crank the engine, aiming the timing light at the harmonic balancer and timing tab. The timing marks should be aligned when the timing light flashes. Timing is controlled by the engine management computer. If timing is off, either the timing belt has slipped and needs to be replaced, or the computer is faulty, and must be replaced.

    4

    Check for compression. If the vehicle still will not start, remove the number one spark plug, and install the compression tester adapter. Turn the engine over for a few seconds, and take the reading from the compression tester. It should be in the 100 psi range. Take a compression reading from the remaining cylinders. The reading should not vary more than 10% from any other cylinder. If it does, or if compression readings are low, there is an internal engine problem that will require extensive engine repair. Consult a professional for diagnosis and options for repair.

My Car Won't Start & Clicking Sounds

My Car Won't Start & Clicking Sounds

Walking out to your car when you are late for work only to discover that the car won't start is aggravating. You are expecting to hear the motor but all you get is a clicking sound. If your car won't start, but it makes a clicking sound, that could mean that the battery is dead or the terminals may have corroded.

Instructions

    1

    Open the hood of your car. Most cars have a lever inside the cab that you pull before you can open the hood. Feel under the hood with your fingers for the lever. The lever is located just under the hood in the front middle section. Pull the lever toward you and push the hood up.

    2

    Put on safety glasses to protect your eyes.

    3

    Remove the black cable from the battery with a wrench. Only loosen the bolts, do not remove them.

    4

    Take a stiff wire brush to remove any corrosion on the cables and battery terminals. Be very careful when doing this so you don't flick any of the corrosive substances in your face. Use a small wire brush to clean inside the clamp. If you need extra power to remove the corrosion, use a mixture of baking soda and water. It should resemble a thick paste. Scrub the cable ends with some steel wool and your wire brush.

    5

    Remove the red terminal cable. This one is the positive side of the battery. Clean this cable as you did in step 3.

    6

    Reinstall the red cable first and then the black one. Try to start your car. If your car still won't start, but your engine still clicks, then you will need to charge the battery.

    7

    Hook up the battery charger, but do not plug it in yet. Place the black clamp onto the black battery terminal and then the red clamp onto the red battery terminal.

    8

    Set the meter to charge on 2 amps or trickle charge. If you are in a hurry, you can set it to a higher setting, but this is bad for your battery.

    9

    Plug in the battery charger. Allow it to charge according to the battery charger manufacturer's directions. Some chargers will indicate a fully charged battery with a green light.

    10

    Unplug the battery charger when your battery is fully charged. Remove the red clamp and then the black one, in that exact order. Close the hood and start your car.

Problems With Running Lights in a 2006 Jetta 2.5

Problems With Running Lights in a 2006 Jetta 2.5

The 2006 Volkswagen Jetta 2.5 has one recall and several technical service bulletins for problems with the running lights. More than 340,000 Jetta's were recalled for running light problems, dealing primarily with roadway illumination and not meeting reflective standards published by the National Highway Traffic Safety Administration.

Running Lamp Recall

    The reflective devices of the running lamps on the 2006 Jetta 2.5 do not meet the National Highway Traffic Safety Administration standards. These reflectors are located on the front and sides of the Jetta and do not illuminate bright enough during normal operation of the automobile. The Jetta must be taken into the dealership to have this recall repaired by replacing the reflective devices. When these devices do not illuminate enough, other drivers can not see the Jetta at a safe distance or safe enough distance to ensure stopping time or to prevent an accident.

Cap Installation

    The recall that deals with the defective reflective devices also deals with the cap that disables the running lights' horizontal and vertical aiming. The 2006 Jetta 2.5 was manufactured without the required cap that disables the aiming of the horizontal running lights. Other Jettas were manufactured with a cap that disables the vertical aiming screw of the vertical running lights. Both of these manufacturing defects create problems with the running lights, preventing them from illuminating the roadway enough for the car's driver. The running light assemblies must be inspected to ensure that the correct cap is installed on the Jetta 2.5.

Range Control Motor

    The 2006 Volkswagen Jetta 2.5 has a technical service bulletin published by the manufacturer concerning the range control motor on the running lights. Once the aiming cap and the reflective devices are fixed by the manufacturer, problems can occur with the range control motor and cause the motor to fail. This failure of the range control motor causes the running lights to blow out or not illuminate in the proper direction under normal driving conditions. The range control motor must be replaced by the dealership once the failure occurs.

2006 Dodge Charger and Shifter Problems

The Dodge Charger, a performance sedan available in all-wheel drive, was introduced in 1966. Although originally manufactured as a muscle car, the 2006 Charger is an affordable sedan. Edmunds.com rated it as one of the best on the market for that model year.

Problem

    Dodge Charger technical service bulletins (TSBs) report that shifting problems are common with the 2006 model. The majority of problems occur when upshifting from first to second gear. TSBs indicate that this "rough" shifting is often accompanied by "shuddering."

Cause

    TSBs indicate that the primary cause of shifting problems is a faulty transmission control module (TCM), which controls the functions of the transmission. A failing TCM cannot reliably tell the transmission when it is time to shift gears, which results in harsh shifting and slippage.

Recall

    Dodge issued automatic transmission powertrain recalls on the 2006 Charger in 2005 and 2008. One recall addressed the park pawl anchor shaft; the other concerned the gearshift cable. Failure of either mechanism may result in the vehicle rolling even after the driver has shifted into park.

Reasons Why an SES Light Stays On

Reasons Why an SES Light Stays On

A SES, or Service Engine Soon light, that stays on is an annoying problem. More importantly, a lit SES light may indicate a problem that needs attention to avoid damaging the vehicle's engine, emissions control system or other components. To understand why the SES stays on, a vehicle owners should understand how the SES light works and how to properly diagnose the problem.

SES Function

    The SES light, also referred to as the check engine light, indicates a problem in the engine control system. The SES light illuminates when a problem occurs. On some vehicles, the light goes off after the problem ends, and on others the light stays on until a repair technician resets the diagnostic system. The system saves a fault code that indicates what caused the problem. Though the system has other purposes, the primary purpose of the SES light is to indicate problems that cause an increase in exhaust emissions.

Common Causes

    Simple problems, such as a loose gas cap, may cause a SES to come on. However, in most cases the problem relates to the diagnostic system indicating high levels of pollutants in the exhaust. The system may indicate this due to an increase in the amount of pollutants in the exhaust or due to malfunctioning or damaged exhaust sensors. When an SES light comes on, the owner or a repair technician should inspect and test the emission control sensors (oxygen sensor, EGR valve). Improper combustion is the usual cause of increased pollutants. Fouled or worn spark plugs, clogged air intakes, improper engine timing and failed engine sensors are some of the causes of improper combustion.

Code Readers

    Diagnostic code readers plug into an access port into the vehicle's diagnostic system and indicate the cause of the illuminated SES light. Auto parts stores sell code simple code readers that can help a vehicle owner determine why the light is on. However, many of these same parts stores will also provide a more thorough diagnostic test for customers without charge. Depending on the source of the problem, the part store personnel can provide information to the vehicle owner on how to complete the required repair. Auto repair shops can also perform these tests.

Repairing the Problem

    Even if the problem is minor, vehicle owners should have the needed repair completed. By failing to fix the problem, the vehicle owner will not know if a more serious problem occurs as the light is already on. Neglecting to fix a minor problem may cause a driver to operate a vehicle with more serious problems that can result in significant and expensive damage to the vehicle. In some states, inspection stations read the vehicle's codes and may fail the vehicle for having a lit SES light.

Senin, 14 Desember 2009

The Symptoms of a Noisy Alternator

The Symptoms of a Noisy Alternator

The alternator is the power generation system in your engine. When the alternator is running properly, it charges the battery as long as the car is running. If the alternator does not work or is improperly providing power to the battery, the car will only be able to run for a few minutes on battery power alone. If you have a noisy alternator, you can begin to diagnose the problem yourself by selectively eliminating a series of issues one at a time until you find the problem.

Loose Drive Pulley

    Check the drive pulley for rattling by holding it with your hand and testing it by shaking it back and forth. There should be very little play. If the pulley is loose, tighten the pulley by using a wrench on the pulley nut in the center.

Loose Mounting Bolts

    The alternator is held in place by a series of mounting bolts. Occasionally they become loose over time, causing the alternator to rattle. Check the bolts and tighten as necessary.

Worn or Dirty Alternator Bearings

    If the bearings in your alternator are worn or dirty, the drive-shaft of the alternator will have a hard time spinning freely, causing heat to build up and extra strain on the alternator. If the alternator does not spin freely, the bearing may be worn and the entire unit may need to be repaired or replaced by a professional.

Defective Stator

    The stator inside the alternator is a series of electro-magnets that creates the AC current to charge the battery. If the stator is bad, it may no longer be providing sufficient power to charge the battery. You will need to test for open circuits and for a proper ground connection in the stator

How to Check the Engine Light on a Subaru Legacy

How to Check the Engine Light on a Subaru Legacy

The Subaru Legacy has always been a dependable car, but even the best cars have problems. When the check engine light (CEL) comes on, it can be a cause for concern. The CEL indicates that something is wrong with your car, specifically the emissions system. The problem can be as simple as a loose gas cap, or it could be something more serious. Subaru Legacy CEL codes fall into two categories. OBD-I is the system used before 1996, and OBD-II is the CEL system that has been used since then.

Instructions

1995 and Older (OBD-I)

    1

    Remove the bottom dash panel. The panel runs from the bottom of your steering wheel toward your gas and brake pedals. It should simply pop off.

    2

    Locate the two pairs of disconnected wires. One pair is narrow and black, and the other pair has wide green connectors.

    3

    Connect the black wires. Turn the ignition to "ON" but do not start the car.

    4

    Record your CEL flashes. There will be a combination of sustained flashes and quick flashes. The number of sustained flashes is the first digit of your CEL code, and the number of quick flashes is the second digit of your CEL code. For example, three sustained flashes followed by three quick flashes would be code number 33.

    5

    Check your deciphered CEL code with your year-specific service manual to find what the code means.

1996 and Newer (OBD-II)

    6

    Remove the lower dashboard panel that's under the steering wheel on the driver's side.

    7

    Locate the diagnostic connection cable. The cable will not be connected to anything and the plug should resemble the one on your OBD-II scanner.

    8

    Plug your scanner into the diagnostic cable. Turn the ignition to "ON" but do not start your car.

    9

    Read the code displayed on the scanner. Cross-reference the code with your year-specific service manual to identify the problem.

Symptoms of a Bad PowerStroke Injector

Symptoms of a Bad PowerStroke Injector

The PowerStroke fuel injection system is designed for diesel burning vehicles. It uses a combination of the hydraulic injectors of old diesel engines and the electric injection system of gasoline engines to provide diesel vehicles with a reliable means of fuel injection. The PowerStroke fuel injector is not without flaws; there are several ways to tell if your PowerStroke injector is in need of adjustment.

White Smoke

    Smoke is the easiest way to tell what is wrong with a PowerStroke fuel injector. White smoke is normal on startup, but excessive white smoke could mean a loose injector or low compression.

Black Smoke

    Black smoke is normal on hard accelerations, but excessive black smoke means the fuel-to-air ratio is too high. Black smoke can also be attributed to restricted intake or exhaust, or a leak in the intake hose.

Blue Smoke

    Blue smoke is normal when the engine is cold, but excessive blue smoke means the air-to-fuel ratio is too high. Blue smoke can also result from contaminated fuel or a plugged injector.

No Start/Hard Start

    If the truck struggles when starting or does not start at all, it could be a sign of a bad injector. If this happens during cold starts only, it is most likely due to a loose or faulty glow plug. If this occurs during hot starts as well, it could be due to a multitude of issues, including a faulty oil pump, leaking injector o-ring or a computer malfunction.

Rough Idle/Loss of Power

    A rough idle and/or loss of power while accelerating is generally associated with thick or incorrect oil, but it may also be related to deteriorated injector o-rings.

Minggu, 13 Desember 2009

Problems With an Automatic Gearbox

Problems With an Automatic Gearbox

The automatic gearbox, also known as the automatic transmission, can experience various operational problems over time. The gearbox transmits engine power (torque) to the rear wheels through a series of graduated gears, doing so smoothly and with perfect synchronization. The transmission fluid functions as the liquid power source that switches and drives the gears under pressure while keeping the interior parts lubricated and cool. There are some warning signs to look out for when the automatic gearbox begins to fail.

Low Fluid Level

    The most common reason for automatic gearbox slippage, overheating or non-operation will be inadequate transmission fluid in the system. If the transmission fluid gets too low, the remaining fluid cannot be picked up by the pump and circulated through the system. Less fluid translates to reduced temperature control, which leads to overheating and transmission fluid that will lose its viscosity (thickness). Major gearbox slippage can result.

Dirty Gearbox Filter

    Automatic gearboxes have a filter screen device located in the main pan. The filter traps all metal shavings and foreign debris and keeps them from entering the delicate channels and passages in the gearbox valve body. Dirty or contaminated gearbox fluid will not have a clean red color, but look muddy or yellow. Dirty fluid can also "froth up" and resemble the consistency of a milkshake, both in color and feel. This condition allows too much air into the channels which will keep the pump from maintaining an equalized pressure. Burnt fluid will have a smoky or acrid smell, and results from old, dirty or contaminated fluid. Checking the fluid at the dipstick can alert the vehicle owner to this problem.

Vacuum Control Device

    Vehicles equipped with vacuum control modules on the side of the gearbox have a vacuum line that runs from the engine to the gearbox. The strength of the vacuum determines when the gears will shift at the proper speed. If the vacuum line leaks, it can force the gears to shift at a too high or low RPM. If the vacuum line has become disconnected, the gearbox might not shift at all. The line and connection should be in good condition and tight at the fitting.

Leaks

    The gearbox will leak mostly from external sources since its design is a closed system. Leaks can be found at the dipstick filler tube base, at the gearbox drain plug, at the linkage connection with the gearbox, at the speed sensor or cable, or at the gearbox cooling lines that enter the bottom of the radiator. If the input or output gearbox shaft seals have worn, there will be a leak at the end of the gearbox tail shaft (near the front drive-line U-joint) or at the bottom of the bell housing. All leaks should be tracked down and repaired.

Gearbox Shift Linkage

    The gearbox shift linkage consists of levers and rods that shift the various drive positions, activated by the manual shifter lever in the vehicle. Disconnected or bent linkage levers and arms will keep the shift selector from choosing the proper gear, such as park, reverse or drive. Linkage connections should be checked for tightness at the points where they join the gearbox levers.

Bands and Clutches

    The gearbox has bands and clutches inside that engage each gear, beginning with first gear and up to the highest gear. The bands function just like a pressure plate on a manual gearbox, and the clutches operate (grab) just like a manual clutch. An automatic gearbox might slip in one or two gears only yet function normally with the others. This sign points to worn clutch material or weak bands inside the automatic gearbox. This condition can only be repaired by a professional transmission service shop.

Nissan Code P1448

Any car or truck built after the 1995 model year comes equipped with an on-board diagnostic (OBD) computer. This device monitors the vehicle's operation, especially its emissions control system. The computer notifies the driver of any fault it detects and a diagnostic code is stored in memory to identify the problem.

History

    The U. S. Clean Air Act of 1990 required OBD monitoring of passenger cars and light trucks beginning with the 1996 model year. The main purpose of the diagnostic computers, called OBD-II in the automotive industry, is to reduce tailpipe emissions by keeping vehicles running efficiently.

Malfunctions

    An OBD-II computer monitors an array of sensors, most in the engine and emissions control system. When a sensor reading falls outside a specified range, the computer illuminates the "Check Engine" light and stores a trouble code in its memory. In post-1995 Nissans, you can read this code with a hand-held scanner.

Code P1448

    P1448 is a proprietary code with different meanings for different vehicles. In cars and light trucks built by Nissan, the code indicates an "EVAP Emission Control System Vent Control Circuit (Open)" condition. The solenoid that opens and closes a vent in the evaporative canister has malfunctioned. This vent is used only during diagnostic tests, although a malfunction prevents diagnosis of other emission control problems.

Jumat, 11 Desember 2009

How to Test Oxygen Sensors With a Voltage Meter

A failed oxygen (O2) sensor will have a direct impact on your vehicle's engine performance. You might notice an increase in fuel consumption, which in turns affects exhaust emissions. But before you blame the sensor or head to the repair shop, run a few tests to check the component's operating condition. You can perform a simple troubleshooting and maintenance procedure with the help of a voltmeter.

Instructions

    1

    Drive your car for about 20 minutes at highway speed to bring the engine to operating temperature, then park the vehicle where you plan to test the oxygen sensor.

    2

    Raise the front of your vehicle with a floor jack and support it on two jack stands, if you need to gain access to the oxygen sensor. Different vehicles have different requirements for testing the sensor. Apply the parking brake and block the rear wheels with two chocks.

    3

    Start the engine and let it idle.

    4

    Connect the red probe of your 10 megohm digital voltmeter to the signal wire of the oxygen sensor through the sensor's electrical connector. Connect the meter's black probe to a metal component or bolt on the vehicle's chassis.

    5

    Set the meter to the mV direct voltage scale. Turn on the meter. The reading on the display should fluctuate rapidly between 0.1 and 0.9 volts (100mV and 900 mV).

    6

    Ask an assistant to pull off a vacuum hose, like the one connected to the positive crankcase ventilation (PCV) valve. The valve is about half the size of a spark plug. Is mounted on or connected to the valve cover with a hose on one side, and connected to the intake manifold with another hose on the other side. The extra air going into the engine should make the sensor output voltage go down to 0.2 or 0.3 volts (200 mV or 300 mV), which indicates a lean air/fuel mixture. Replace the vacuum hose.

    7

    Ask your assistant to open and close the throttle valve by hand. The throttle valve swings at the center of the throttle body when the accelerator pedal is depressed. The oxygen sensor voltage signal should change rapidly, reacting to the sudden change in the air going into the intake manifold.

    8

    Disconnect the air duct from the air intake assembly with a Phillips screwdriver and ask your assistant to block the opening with a shop rag. The air intake assembly connects the throttle body to the front of the vehicle with an air duct and contains the air filter.

    You can disconnect the air duct at the throttle body or air filter housing, depending on your vehicle. The oxygen sensor output voltage should rise to about 0.8 or 0.9 volts (800 mV or 900 mV) as the air going into the intake manifold is decreased.

    9

    Turn off the engine and lower your vehicle off the safety stands, if you had to raise it. If your oxygen sensor fails to react to the changes in air content, you need to replace it.

Can Bad Spark Plugs Cause Detonation?

Can Bad Spark Plugs Cause Detonation?

Spark plugs are calibrated electrical malfunctions in the same way a carburetor is a metered fuel leak. Spark plugs operate under some of the harshest conditions imaginable, but must continue to perform thousands of times a minute without fail. This requires some very precise engineering and controlled tolerances; any imperfection in the system can easily force the spark plug to do things it was never meant to do.

Plug Basics

    A spark plug is basically an opening in the ignition system's circuit -- a carefully calibrated gap that forces electrical current to turn into a spark in order to bridge it. Air and fuel are explosive in and of themselves, but become far more volatile when heated. Compressing air causes its temperature to rise by nearly a factor of the compression ratio. Even under the best of conditions, this compression heat alone brings the air/fuel mixture very close to its autoignition point. Any excess pressure, ambient heat or hot-spots in the chamber can tip the thermodynamic scales and detonate the mixture prematurely.

Types of Detonation

    There are two types of engine knock or detonation: abnormal combustion and pre-ignition. While often used interchangeably, these terms are actually completely different phenomena. An air/fuel mixture doesn't normally explode -- it burns away from the spark plug in an expanding "balloon" called the "flame front." Abnormal combustion happens after the spark plug fires rapidly and pressure rises in the chamber, causing some pocket of air and fuel outside of the flame front to ignite. This detonation may happen as a result of a pressure rise from the plug's flame front. Pre-ignition happens when the all or some of the air-fuel mixture detonates before the spark plug goes off.

Plug Fouling and Detonation

    A physically damaged spark plug generally will not cause detonation, since most types of physical damage just inhibit spark energy and electrical transfer. However, carbon buildup -- usually a result of oil or soot in the intake stream -- on the plug will capture heat and begin to glow an intense red- or white-hot. Once that happens, you've got a glow plug instead of a spark plug. These carbon deposits "only" burn at about 700 to 1,000 degrees -- far less than the spark's millisecond-long discharge of 105,000 degrees or so -- but that's more than enough to pre-ignite an air/fuel mixture under pressure.

The Wrong Plug

    The wrong spark plug can just as easily cause detonation as one that's gone bad. Look down into the tip of a spark plug and you'll see a white, ceramic insulator. This insulator conducts heat away from the plug tip and into the body; the more ceramic there is, the more heat it can conduct away from the plug. High-compression, turbocharging, supercharging and nitrous-injection all create very high temperatures and pressures in the combustion chamber, making the mixture more prone to detonation. These setups demand a "colder" plug -- one with more insulation. Under these conditions, a hotter-range plug -- generally a boon for fuel economy and horsepower -- will build up heat and turn into a glow plug.

How to Check Fuel Pressure in a 1993 Cutlass

How to Check Fuel Pressure in a 1993 Cutlass

In order for your 1993 Cutlass to run properly, its fuel system must maintain constant and consistent pressure throughout the fuel lines. If your engine fails to turn over or if it sputters and halts during operation, it could be a problem with your fuel lines or fuel pumps, problems you can diagnose by checking the fuel pressure. Unfortunately, since the early 1990s, most cars -- including your Cutlass -- require an expensive, master fuel injector pressure test kit in order to test the fuel line pressure. Without one of these kits, you will need to take your vehicle to a local mechanic and have them test your Cutlass's fuel pressure.

Instructions

    1

    Pop your hood and locate your fuel line, the fuel rail, and the clip connecting the two. The clip is located slightly to the driver's side of the engine block.

    2

    Remove the clip connecting your Cutlass' fuel line to the fuel rail using a fuel line key. A fuel line key can be purchased at your local auto-parts store.

    3

    Insert your fuel injector pressure test kit into the gap created by removing the clip connecting the fuel line and rail. Ensure that the attachment end is connected to both the fuel line and the fuel rail.

    4

    Hang the meter end of the pressure test kit from the hood of your car.

    5

    Turn your Cutlass on.

    6

    Check the reading on the meter. For your '93 Cutlass, the meter should read about 42 psi and it should hold steady for the duration of the test.

How to Troubleshoot a Car Alarm Keypad That Does not Light Up

How to Troubleshoot a Car Alarm Keypad That Does not Light Up

Car alarms are available as optional or stock equipment by the manufacturer, or they can be installed as an aftermarket option. The alarms supplied by the manufacturer tend to be operated using the wireless transmitter that is used to open the doors. Aftermarket systems can be a lot more elaborate, and the keypads can resemble home entertainment remote controls, complete with LED lighting. Car alarm keypads that don't illuminate can be fixed by following a few steps.

Instructions

    1

    Change the battery in the alarm keypad if the backlight doesn't illuminate and the alarm can't be operated by the keypad either. In this case, the batteries have become exhausted. Examine the remote and remove the battery cover. It's usually on the back and slides off, or it can be levered off with a coin. Insert new batteries. In the case of an automaker-supplied remote, the coin-type batteries usually install with the positive icon facing outwards.

    2

    Program the aftermarket alarm keypad properly if the keypad doesn't light up, but the keypad operates the alarm system. Enter the programming function for your particular alarm (consult the owner's manual for specific instructions). Scroll through any settings to select "Backlighting," or a similar label, and turn the illumination on. The keypad might beep once to let you know you've turned it on.

    3

    Look for any light buttons if the alarm keypad still won't light up. The keypad will often have an illumination function represented by a light bulb icon. Press it to turn the illumination on. If the illumination goes off rapidly, it's likely to be a power saving function and is normal. Press the light-bulb icon button again.

Kamis, 10 Desember 2009

What Would Happen If a Timing Belt Slipped?

Timing belts may be quiet, smooth and inexpensive to produce and replace, but you can't help but question the logic of using a piece of rubber to connect the two most vital rotating components in your engine. Fortunately, most timing belts give plenty of notice before they either snap or fail completely; in this sense, the symptoms that accompany a jumped tooth can be something of a blessing in disguise.

Basic Failure

    Timing belt failure comes in three flavors: stretching, worn teeth and snapping, generally in that order. All timing belts stretch, and most of that stretch occurs about 15 minutes after installation. A spring-loaded tensioner keeps the belt tight, but after a while the tensioner will run out of travel and the belt will go slack. Simultaneously, the metal teeth on the cam and crank sprockets will slowly round off the edges of the belt teeth, turning those neat teeth into sad little bumps. This, combined with belt slack, will cause the crankshaft to pull ahead of the camshaft. The "retarding" of the cam causes the valves to open and close later than they should.

Exhaust Smoke

    Excess exhaust smoke, or rather a cloud of black smoke that reeks of unburned gas, is a pretty good indication that something's gone awry with the timing belt. When the camshaft retards by a few degrees, the intake valve will open and close well after it should. This will quickly dump pressure from the combustion chamber, resulting in an incomplete fuel burn and raw hydrocarbons escaping from the exhaust port. On a computer-controlled car, the oxygen sensor will detect this excess of fuel and the computer will reduce the amount of fuel injected to compensate. At the very least, you'll get a check engine light and a "rich condition" code from the computer.

Loss of Power

    An engine that isn't burning all of its fuel isn't making the power that it should be, but that's not the only thing going on here. The pressure drop from the late valve opening and closing means that your motor will experience a loss in power simply due to the lost compression. Old, stretched timing belts will do the same thing, albeit to a lesser degree and so progressively that you might not notice it aside from the fact that the engine doesn't feel as snappy as it used to.

Misfire and Difficulty Starting

    What all of this adds up to is a little thing mechanics call "misfire." A misfire will result from anything less than perfect combustion, and that's obviously the case when your valves aren't opening on time. Many engine problems can cause a single-cylinder misfire, but a belt that has jumped a tooth will cause every cylinder to misfire. At some point, the engine will misfire so badly that it either won't run or won't start. Difficult starting, combined with a loss of power, heavy engine vibration as a result of misfire and raw fuel spewing from the engine are the most classic signs of an engine which has jumped timing.

Click, Click, Boom

    If you suspect that your engine has jumped timing, don't just let it go and hope for the best. Once the engine jumps a single tooth, it's only a matter of time before it does it again and leaves you stranded or worse. At the very least, you'll want to do some research and find out if your engine is an "interference" design. If the belt or a chain snaps on an interference engine, the pistons will crash into the open valves and your motor will self-destruct like a former child star at a vodka distillery.

Rabu, 09 Desember 2009

What Are the Causes of Ignition Fuses Blowing?

Fuses are current overload protection devices, specifically engineered to act as the weak link in an electrical circuit. A fuse keeps a circuit from passing excess current and destroying whatever's attached to it or melting the wires and starting a fire. Automotive ignition fuse malfunctions pose a few unique problems, primarily since they're usually not the only thing on that circuit.

Fuse Basics

    Fuses come in all types and varieties, but they all work in a similar fashion. Current passes through the fuse via a small metal strip or a spring; that small metal strip creates a sort of bottleneck in the system, a point of high impedance where electricity will slow down and turn into heat. Once that strip gets hot enough, it melts, snaps and breaks the circuit connection. So, to find the source of your problem, you'll need to look for an electrical short circuit that pulls more energy through the system than it was designed to handle.

Multiple Circuits

    The problem with automotive electrical troubleshooting is that multiple systems often run through the same circuit or fuse. For instance, your ignition system might share its power source with the starter, fuel pump, fuel injectors, ignition control computer or that flashing skull shifter knob you bought from Pep Boys. So, the malfunction might not even be in your ignition system; it could be a malfunction or short circuit in any of the connected systems.

Ignition System Faults

    The good news is that there aren't too many things in the ignition system itself that can blow your fuse, particularly if the the ignition coil draws its current directly from the battery or alternator via a relay. If that's the case, then your fault is almost certainly in the ignition switch itself or the wires going to it. Within the distributor itself, a bad or bypassed ballast resistor can repeatedly blow fuses, but that's unlikely unless some hack mechanic did a bad wiring job on it. A bad coil might blow fuses, but it'll more than likely kill the engine before that happens.

Ancilliary Faults

    If your ignition system shares a common circuit with something motorized -- a fuel pump, cooling fans, power window motor, starter, etc. -- then that's likely the source of your fault. Electric motors always draw a certain amount of wattage, or amperage multiplied by voltage. Higher voltage makes the motor spin faster, more amperage causes it to produce more torque. If the motor seizes up or something forces it to slow down, voltage draw will drop and amperage draw will increase to maintain the same wattage. This can easily blow a fuse, particularly if it's already heavily loaded by something as power-hungry as the ignition system.

Wiring and Computer Faults

    Inspect your wires carefully; hot parts on the engine can easily burn through the wiring's insulation and short the wires, and metal edges will cut through the wires and short them out. If you've got fuel injection, then you might be experiencing an internal short in the computer itself. In that case, you're out of luck; it's off to the parts store or junkyard for a new computer.

1995 Ford Taurus Will Crank But Won't Start

1995 Ford Taurus Will Crank But Won't Start

As cars age, they require more maintenance and troubleshooting as various components of the vehicle's mechanical systems will need repair or replacement. The reason why your 1995 Ford Taurus will crank, but won't start, may be simple or complex. The problem might be caused by something as simple as a clogged fuel filter. Or, the Taurus may not start because of a faulty timing chain, which involves a more time-consuming and costly repair. With some mechanical know-how, you can troubleshoot the problem yourself and avoid paying a repair bill.

Instructions

    1

    Verify that the vehicle has fuel in the tank. You might be getting a false reading from the fuel gauge. If you can't remember how many miles you've driven since your last fill-up, add a gallon of fuel to the tank and attempt to restart the vehicle. If the vehicle was out of gas, you will have to crank the engine for at least 30 seconds, to allow the fuel to travel from the tank to the engine and work any air out of the fuel line.

    2

    Check the pressure in the fuel system with a fuel pressure test gauge. Attach the test gauge past the fuel filter, which is along the frame on the passenger side of the car. A 1995 Ford Taurus should have a fuel pressure in the range of 26 to 45 psi when cranking the engine. If there is no or low pressure, replace the fuel filter and retest. If a pressure problem still exists, the fuel pump has failed and needs to be replaced.

    3

    Remove the spark plugs using a spark plug wrench and inspect the tips. If they have an excessive amount of fuel or black carbon residue, they will not be able to provide sufficient spark to ignite the fuel and start the vehicle. Replace the spark plugs and attempt to start the vehicle again.

    4

    Check the engine for proper compression by removing a spark plug and attaching a compression gauge into that cylinder. When cranking the engine, you should have a reading of between 125 to 160 psi on that cylinder. Low or no compression most likely is a sign that the timing chain has failed and needs to be replaced.

How to Troubleshoot Chevy Trucks

How to Troubleshoot Chevy Trucks

Chevy has manufactured numerous different truck models with varying engine sizes. All of the trucks require electricity, fuel, a spark and combustion to run but different models require different troubleshooting methods. All of the trucks manufactured after 1995 have the ability to display engine problems through a diagnostic reader. All of the models manufactured before 1995 must be diagnosed by making mechanical observations. You can narrow down the potential problems by listening and feeling for changes in your truck's performance.

Instructions

    1

    Turn the key and test the truck for power. Flash the headlights and pay attention to the dash lights for flickering. If the power is inadequate, use jumper cables and a second vehicle to jump start the truck. If the battery continues to lose power, replace it and test the alternator with a voltage meter. Replace the alternator if it malfunctions.

    2

    Open the hood and roll down the windows if the engine does not crank. Turn the key and listen for a clicking sound. The sound means the starter teeth are locked and the engine will not start until they are unlocked or a new starter is installed. Tap the starter with a hammer to unlock the teeth. Also, consider removing the starter and having it tested at an auto parts store.

    3

    If the engine cranks but does not start, the vehicle is missing fuel or missing a spark. Replace the spark plugs and attempt to start. If it fails, the carburetor or fuel injection system requires servicing.

    4

    Drive the vehicle on a smooth surface. If the engine experiences power surges, the fuel pump may be going bad. The surges indicate a lack of fuel being delivered to the engine. If the vehicle is difficult to steer, the power steering pump require replacement. Difficulty steering is also attributed to an engaged four-wheel drive system. If the vehicle is locked in four-wheel drive, the transfer case must be serviced.

    5

    Drive the truck at variable speeds to test the transmission. If the automatic transmission stalls before shifting, it must be serviced. On manual models, a bad transmission will make it difficult to find the correct gear and the clutch will feel really loose.

How to Reset Saab Readiness

Saab is a popular line of Swedish cars, featuring many of the latest automotive technologies. Your Saab's doors, locks, trunk and engine can be controlled with a keyless entry system. You can program your Saab's key by syncing it with the remotes to your transmitter. The process is simple, and all you need are your ignition key and remote.

Instructions

    1

    Insert your key into the ignition and pull your multifunction lever towards you and hold it there.

    2

    Turn the ignition key on then off two times.

    3

    Release the lever while the key is in the "Off" position. You should hear the horn beep twice, indicating that you've entered the programming mode.

    4

    Push the "Lock" button on the remote within 30 seconds after the programming has begun.

    5

    Wait for the locks to respond after you press the button on the remote. Once you pull the key out of the ignition, the trunk lock has been reset.

Selasa, 08 Desember 2009

My 1995 Ford Explorer Won't Engage the 4-Wheel Drive

My 1995 Ford Explorer Won't Engage the 4-Wheel Drive

Some 1995 Ford Explorers were sold with a four-wheel-drive system which, when selected, enabled the vehicle to use all four wheels to power forward. This improves traction, so you can take the vehicle places ordinary two-wheel-drive cars can't go. The 1995 Explorer's four-wheel-drive system is particularly well-suited to slippery conditions, and the included low-ratio four-wheel-drive option is suited to sand, mud, snow and deep water. If your Explorer won't engage the four-wheel-drive, you can solve it by operating the system properly.

Instructions

    1

    Wait until none of the SUV's wheels are slipping if you are unable to shift the Explorer into four-wheel drive from two-wheel drive. Then rotate the dashboard knob from the "2WD" position to position marked "4WD Auto" to engage four-wheel drive. You may hear some clunking and under-floor noises, but that's normal.

    2

    Stop the SUV if the Explorer won't go into "4WD Low." Press the clutch down, or, for automatic transmissions, place the Explorer into "Neutral." Then rotate the switch to the "4WD Low" position.

    3

    Wait for a minute if the Explorer still won't shift. Shifting may be delayed if the ambient temperature is below zero. Other variables that can affect the speed of shifting include tire pressure, worn tread and loading. Check the sticker on the driver's-side doorjamb and make sure that you are in compliance with the requirements printed there.