KOEO Self-Test

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 on gasoline vehicles. Turn ignition off. Wait 10 seconds. Ensure test equipment is properly attached. Turn ignition on (engine off). Record all KOEO and Continuous Memory Codes.

If a Code 11 or 111 (pass code) is not retrieved in KOEO portion of test, service KOEO codes. See SERVICE CODE REFERENCE CHARTS  . If ECA will not output codes, go to CIRCUIT TEST QA. If service codes are retrieved:

• If CHECK ENGINE or SERVICE ENGINE SOON light is on, service codes in order retrieved. See SERVICE CODE REFERENCE CHARTS  .
• On DIS and EDIS models, see IGNITION SYSTEM in I - EEC-IV SYS/COMP TESTS article in the ENGINE PERFORMANCE Section if Continuous Memory Code 45, 46, 48, 215, 216, 217, 232 or 238 is retrieved during KOEO SELF-TEST.
• If vehicle has a no-start condition, go to CIRCUIT TEST AA (TFI), CIRCUIT TEST AB (DIS) or CIRCUIT TEST AC (EDIS).
• If vehicle displays a Code 11 or 111 (pass code) and does not have any of symptoms described in previous steps, go to COMPUTED TIMING CHECK.