KOEO Self-Test

Ensure engine is at 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 Code 11 or 111 (pass code) is not retrieved in KOEO portion of test, service KOEO codes at this time. Service any engine codes recorded before servicing transmission codes (Codes 86, 89, 566 and 629). If ECA will not output codes, see TESTS W/CODES - EEC-IV article in ENGINE PERFORMANCE section. If service codes are retrieved, observe following procedures:

• If CHECK ENGINE or SERVICE ENGINE SOON light is on, service codes in order retrieved.
• On vehicles equipped with DIS and EDIS ignition systems, see SYSTEM/COMPONENT TESTS - EEC-IV article in ENGINE PERFORMANCE if Continuous Memory Code 45, 46, 48, 215, 216, 217, 232 or 238 is retrieved during KOEO SELF-TEST. Repair ignition system as necessary.
• If vehicle has a no-start condition, go to appropriate NO-START CIRCUIT TESTS in TESTS W/CODES - EEC-IV article in ENGINE PERFORMANCE.
• If vehicle displays Code 11 or 111 (pass code) and does not have any of symptoms described in previous steps, go to COMPUTED TIMING CHECK  .