The 1989 Ford Escort doesn’t use the OBD2 system we’re familiar with today. Instead, it utilizes Ford’s EEC-IV (Electronic Engine Control-IV) system, which has a different diagnostic connector and code reading procedure. This article clarifies how to access and understand the diagnostic system on your 1989 Ford Escort.
Locating the Diagnostic Connector on a 1989 Ford Escort
The EEC-IV diagnostic connector is typically located under the hood, often near the firewall on the driver’s side. It’s a rectangular connector, usually black or gray, with a single row of pins. You may need to consult your owner’s manual for the precise location if you’re having trouble finding it. It is often labeled as the “Self-Test Input” connector.
Running Self-Diagnostics on Your 1989 Ford Escort EEC-IV System
Once you’ve located the connector, you can initiate the self-diagnostic test. This process involves using a jumper wire to connect specific pins on the connector, often labeled as STI and GND. This action puts the EEC-IV system into a diagnostic mode.
With the key in the “ON” position (engine off), observe the “Check Engine” light (CEL) or “Service Engine Soon” light. The light will flash a series of codes, pausing between each code sequence. These codes correspond to specific issues within the engine management system.
Understanding the Flash Codes
Each code consists of a series of flashes. For example, three flashes would represent the number 3. A longer pause separates individual numbers within a code. So, a code like “32” would be three flashes, a pause, then two flashes. After a longer pause, the system will repeat the codes.
The codes typically indicate issues related to sensors, actuators, or other components of the EEC-IV system. Common codes include those for coolant temperature, EGR (Exhaust Gas Recirculation), and air temperature sensors. You can find a complete list of EEC-IV codes in a Haynes repair manual for Ford vehicles of that era or by searching online resources.
Shift Light Operation on a 1989 Ford Escort
The 1989 Ford Escort, particularly models with manual transmissions, may feature a shift light. This light illuminates to indicate the optimal engine speed for upshifting to maximize fuel economy. It’s triggered based on factors like RPM, vacuum pressure, and throttle position. You might notice the light activating around 3000 RPM under light throttle conditions. This doesn’t indicate a mechanical problem but rather serves as a fuel-saving aid.
Achieving Optimal Fuel Economy
Several factors contribute to achieving good fuel economy in a 1989 Ford Escort. Ensuring all engine components are functioning correctly, indicated by the absence of diagnostic trouble codes, is crucial. Regular maintenance, proper tire inflation, and driving habits also play a significant role.
With a properly maintained 1989 Ford Escort, you can expect reasonable fuel economy for its age. While individual results may vary, achieving mileage in the mid-30s is a realistic expectation.
In conclusion, while the 1989 Ford Escort predates OBD2, understanding its EEC-IV system is crucial for diagnosing and addressing potential issues. By locating the diagnostic connector, initiating the self-test, and interpreting the flash codes, you can gain valuable insights into your vehicle’s engine management system. Remember to consult a repair manual for a comprehensive list of trouble codes and their corresponding meanings.
