KOER Self-Test

WARNING: This page is about a different car, the 1994 Mazda B3000 and 1994 Mazda B2300. However, it is still accessible from the selected car via links, so may be relevant.

DO NOT enter this test sequence until a Code 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 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 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 Code 111 (pass code) is retrieved, service Continuous Memory Codes retrieved in KOEO SELF-TEST. See SERVICE CODE REFERENCE.
If a Code 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, go 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.