GM Service Manual Online
For 1990-2009 cars only

Important:  Always start the diagnosis with the Powertrain On-Board Diagnostic (OBD) System Check. This will reduce the diagnostic time and prevent unnecessary parts replacement.

For additional information, refer to the following procedures:

    •  Ignition System Check
    •  DTC P0325 Knock Sensor (KS) Circuit Bank 1
    •  DTC P0330 Knock Sensor (KS) Circuit Bank 2
    •  Spark Plug Visual Diagnosis