GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category

DTC Descriptor

DTC B1023 00: Integral Switch Performance

Circuit/System Description

The driver door module (DDM) and front passenger door module (PDM) each contain switches that control power door lock and window functions. The DDM also contains the control switch for the power outside rear view mirrors. These switches are integrated within the door control modules and are not serviceable as separate components. The DDM and PDM monitor these switch inputs for internal faults and will set B1023 00 if any are detected.

Conditions for Running the DTC

The system voltage is 9-16 volts.

Conditions for Setting the DTC

The DDM or PDM detects multiple or simultaneous inputs from a window or door lock switch.

Action Taken When the DTC Sets

The driver or passenger door module ignores inputs from the malfunctioning switch.

Conditions for Clearing the DTC

    • The DTC will be current for as long as the fault is present.
    • When the fault is no longer present, the DTC will be a history DTC.
    • A history DTC will clear after 50 ignition cycles.

Reference Information

Schematic Reference

Door Lock/Indicator Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Power Door Locks Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Clear all DTCs and operate the integrated switches at each door control module within the Conditions for Running the DTC.

If the DTC resets, replace the affected door module.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for DDM or PDM replacement, setup and programming