GM Service Manual Online
For 1990-2009 cars only

Important: If you have not completed the Vibration Analysis table as indicated and reviewed Diagnostic Aids, refer to Vibration Diagnostic Aids BEFORE operation.

Check Service Bulletins

If BOTH of the following statements are TRUE, then check service bulletins for the condition identified. If the condition has been identified and investigated prior to this vehicle, and has been determined to be something that is not truly an operating characteristic or that perhaps is not design-intent, there will likely be adjustments or corrections identified which will solve the condition.

    • You CAREFULLY followed the steps indicated through reviewing the Diagnostic Starting - Vibration Diagnosis and completing the Vibration Analysis table identified and you have duplicated the vibration concern.
    • You have come to the conclusion that the customer's concern appears to be a potential operating characteristic of the vehicle, through comparison with a very equally - equipped, same model year and type, KNOWN GOOD vehicle.