Diagnostic Workflow
- Verify Complaint. Get detailed information on conditions present when fault occurred.
- Check and write down DTCs and freeze frame data. Erase DTCs.
- Attempt to recreate conditions present when fault occurred (test drive etc.).
- Recheck DTCs and data monitor information while duplication fault conditions.
- If DTCs are retrieved, perform appropriate DTC testing.
- If no DTCs are retrieved or only system okay DTC is retrieved, check suspect wiring for intermittents by wiggling wiring while checking data monitor.
- If no response from scan tool attempted, retrieve DTCs using MIL.
- Check ECM pin voltage values. See the PIN VOLTAGE CHARTS article.
- Ensure fault/symptom is repaired before returning vehicle.