KOEO Self-Test

WARNING: This page is about a different car, the 1994 Mercury Topaz, 1994 Mercury Sable, 1994 Ford Tempo, and 1994 Ford Taurus. However, it is still accessible from the selected car via links, so may be relevant.

Ensure engine is warmed to normal operating temperature. If engine does not start (or stalls after starting), continue KOEO SELF-TEST. DO NOT depress throttle. Turn ignition off. Ensure test equipment is properly attached. Turn ignition on (engine off). Record all KOEO and Continuous Memory Codes.

If a Code 111 (pass code) is not retrieved, service KOEO codes. See SERVICE CODE-TO-TEST REFERENCE MENU . If PCM will not output codes, go to CIRCUIT TEST QA. If diagnostic trouble codes are retrieved:

If MIL/CHECK ENGINE light is on, service diagnostic trouble codes in order retrieved. Refer to SERVICE CODE-TO-TEST REFERENCE MENU .
On distributorless ignition models, see IGNITION SYSTEM in SYSTEM/COMPONENT TESTS - EEC-IV (3.0L) article in the ENGINE PERFORMANCE section if Continuous Memory Code 215, 216, 217, 218, 222, 223, 224, 232 or 238 is retrieved during KOEO SELF-TEST.
If vehicle has a no-start condition, go to: - CIRCUIT TEST AA (DI) - CIRCUIT TEST AB (EI - low data rate) or - CIRCUIT TEST AC (EI -high data rate).
If vehicle displays a Code 111 (pass code) and does not have any symptoms described in previous steps, go to KOER SELF-TEST.