KOER Self-Test

DO NOT enter this test sequence until a Code 11 or 111 (pass code) has been retrieved in KOEO SELF-TEST. If system has not passed KOEO SELF-TEST, codes received from KOER SELF-TEST may not be valid.

Deactivate self-test by removing and reconnecting jumper wire or by procedure specified by manufacturer of test equipment in use. Start engine, and run it for 2 minutes at 2000 RPM to warm Heated Oxygen Sensor (HO2S). Turn engine off, and wait 10 seconds. Activate KOER SELF-TEST using a jumper wire or appropriate procedure for test equipment used. Start engine. Record all service codes displayed.

Check following items:

If Code 98 or 998 is displayed, EEC-IV system is operating in Failure Management Effects Mode (FMEM). PCM has detected an out-of-range sensor and has substituted a fixed value to enable vehicle to continue operation.
If vehicle is equipped with a Brake On-Off (BOO) switch, brake pedal must be depressed and released after ID code portion of test.
On vehicles with Power Steering Pressure (PSP) Switch, turn steering wheel at least 1/2 turn and release within 1-2 seconds after ID code portion of test.
On vehicles with Transmission Control Switch (TCS), cycle TCS switch after vehicle ID code is given.
If Dynamic Response Code appears, perform a brief Wide Open Throttle (WOT). DO NOT perform WOT unless requested.
If a Code 11 or 111 (pass code) is retrieved during KOER SELF-TEST, service Continuous Memory Codes retrieved in KOEO SELF-TEST. See SERVICE CODE REFERENCE CHARTS .
If a Code 11 or 111 (pass code) is retrieved during Continuous Memory Code portion of KOEO SELF-TEST and no driveability problem exists, EEC-IV testing is complete. If driveability problems are still present, refer to TESTS W/O CODES article in the ENGINE PERFORMANCE section.
If KOER codes are present, see SERVICE CODE REFERENCE CHARTS . If system will not output codes, go to CIRCUIT TEST QA.