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For 1990-2009 cars only

Reading Diagnostic Trouble Codes DTCs With a Scan Tool

The body control module (BCM) is able to store DTCs in memory as a current or a history DTC. The recommended method for reading DTCs, stored in memory, is by using a scan tool plugged into the data link connector (DLC). The DLC is located under the instrument panel by the hood release. Follow the scan tool instructions supplied by the tool manufacturer.

Diagnostic Trouble Code (DTC) Diagnosis

This section uses diagnostic tables, wiring diagrams and descriptive text in order to direct you in performing specific tests in order to locate and repair the condition. The diagnostic table is a step by step procedure used in order to determine the circuit or component that is the source of the problem. The wiring diagrams and text describing the system, test conditions, failure conditions and actions taken when a DTC is set are located on the page facing the diagnostic table.

Current Codes

When the BCM determines that a failure condition for a particular DTC is set during the current ignition cycle, the BCM sets the code as a Current DTC. All DTCs remain current until the condition for setting the fault is corrected or the next fault free ignition cycle has occurred. The Current code then will become a History code only.

History Codes

When a DTC is set as a current fault code the DTC will automatically be stored as a history code as well.

A history code can be cleared as follows:

    •  A history DTC will clear after 100 consecutive ignition cycles without a fault present.
    • Using a scan tool.