Self-diagnostic systems date back to Volkswagen's 1969 Type 3, the marque's first non-Beetle car. For the next 27 years, onboard diagnostic system programming was an automotive Wild West, where every manufacturer used whatever system they felt like using. In 1996, the Federal government stepped in to standardize automobile self-diagnostic systems with a programming protocol called On-board Diagnostics, Series 2. This very simple and universal system makes checking and clearing codes a no-skills-required affair.
Locate the OBD-II port on the passenger side of the center console, just below the glove compartment. Remove the plastic or rubber cover from the OBD-II port to access the terminal pins; this connector is the data link that your code scanner will use to communicate with the car's computer.2
Plug the code scanner into the OBD-II port, turn the car's ignition to the "on" position and wait for the scanner to engage the car's computer. Some scanners will automatically recognize the car's manufacturer programming protocol, others will require that you enter vehicle make, model, option package and engine information. Base Escorts got the 2.0-liter, single-overhead-cam four-cylinder engine, and ZX2 models got Ford's dual-cam Zetec 2.0-liter.3
Follow the prompts on your code reader to determine the fault code. If the scanner doesn't carry a code database for Ford, you'll need to compare the code number to an OBD-II database for Ford. You can find such databases online by entering "Ford OBD2 codes" into your web browser, or by simply scrolling down to the Resources link on this article.