For 1990-2009 cars

Clearing History Codes: In order to prevent any future misdiagnosis, clear all history DTCs after diagnosing a system condition.

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

• | A scan tool

• | The On-Board Service Diagnostic (OBSD)

• | A module will clear a history DTC after 50 ignition cycles.

Most of the diagnostic tables refer to the scan tool for diagnostic support. For details on using the OBSD to display and/or clear DTCs, refer to OBSD procedure.