- Powertrain/On-Board Diagnostic System Check

PCM Power And Ground Circuit:

NOTES ON CHART 1:
1. Checking if vehicle will enter diagnostics. If it will not, then there is an on-board diagnostic system fault that can be diagnosed by using the Self-Diagnostic System Check. Testing and Inspection

2. Checking to see if the BCM is able to communicate with the PCM. If it is not, Code B334 will set or "NO PCM DATA" message will be displayed when using diagnostics.

3. "SERVICE ENGINE SOON" MIL should be "ON" when vehicle is in diagnostic mode.

4. Checking if powertrain system is operational.

5. Checking for PCM codes set that should be diagnosed.

6. "SERVICE ENGINE SOON" MIL should be "OFF" with no codes set.

7. Checking if a known customer complaint is causing the problem.

8. If your complaint is not in the customer complaint list, perform the system check which you feel may apply to your situation.