KOEO & KOER Codes (Hard Faults)

These codes indicate a hard fault that is actually present at the time of testing. These hard faults may cause the CHECK ENGINE or SERVICE ENGINE SOON light to come on and remain on until the fault is repaired. If KOEO or KOER codes are retrieved during the Self-Test, see SERVICE CODE REFERENCE CHART  under HOW TO USE CIRCUIT TESTS for testing and repair.