Self-Test Procedures

Perform a visual check of all computer related wiring and connectors. Ensure all electrical, tune-up, fuel system and other basic engine operations are completed or in good working order before checking the EEC-III system. If any trouble codes are found in EEC-III computer memory, refer to the EEC-III DIAGNOSTIC CODES CHART . If necessary, use appropriate test equipment and an electrical diagram to check each circuit indicated. Use the following procedures to trigger self-test operation for all Ford models with EEC-III.

1. Start engine and run at 1800 RPM until upper radiator hose is hot. Connect a vacuum pump to B/MAP vent port.
2. Connect an analog meter positive lead to TAD solenoid (Circuit No. 99). Ground negative voltmeter lead. Apply 20" Hg vacuum to B/MAP and hold for 8 to 60 seconds. Release vacuum.
3. As vacuum is released, throttle kicker solenoid will extend and retract. Voltmeter needle will also pulse 2 times (on EFI engines) or 4 times (on carburetor engines).
4. Throttle kicker will extend and computer will begin self-test diagnosis. After a certain amount of time, throttle kicker will retract. This action indicates the end of self-test mode and computer will transmit a pulsing code to voltmeter.
5. If any trouble codes are present, voltmeter needle will begin pulsing. The 2 digit codes are obtained by counting pulses of needle similar to how the EEC-IV does. Record all codes.