GM Service Manual Online
For 1990-2009 cars only

Important: Clear all of the history diagnostic trouble codes (DTCs) after you diagnose a system condition. This procedure will prevent any future misdiagnosis.

Disconnecting the battery or the module connectors will not clear a history DTC. A DTC may only be cleared by one of the following methods:

    • Use a scan tool.
    • A history DTC clears after 50 ignition cycles.

Most of the diagnostic tables refer to the scan tool for diagnostic support.