ML15 - Malfunction Indicator Light Flashing with Erratic Idle

NOTE: Vehicle symptoms Indicate that Self Test Input (STI) is grounded and the vehicle is actually performing Self-Test without a tester installed.

- Key "OFF".

- Disconnect Powertrain Control Module (PCM) connector. Inspect for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary.

- Measure resistance between the STI circuit at the Data Link Connector and engine block ground.

- Is resistance less than 10,000 ohms?

Yes -- Service short circuit. Reconnect PCM. Verify symptom eliminated.

No -- Reconnect PCM. Verify symptom eliminated. Return to Diagnostic Routines for rough idle diagnosis. Symptom Related Diagnostic Procedures