What this code means

The Key On Engine Running (KOER) self-test was unable to complete. This indicates the PCM could not finish its powered-on engine running diagnostic routine, possibly due to another existing fault or test conditions not being met.

Symptoms

• Check Engine Light
• Self-test cannot complete
• Other DTCs may be stored

Common causes

• Existing DTCs preventing test completion
• Engine not at operating temperature
• Accessories not turned off during test
• PCM malfunction

Diagnostic steps

1. Ensure engine is fully warmed up before running KOER test
2. Turn off all accessories (A/C, lights, radio)
3. Check for and resolve any other stored DTCs first
4. Retry KOER self-test

Repair notes

Resolve other DTCs first, then re-run KOER self-test with engine at operating temperature.

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