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.

Circuit/System Description

This feature allows the operator to simultaneously retract both mirrors to a fully folded position. The driver door module (DDM) contains the power folding mirrors switch and, each mirror contains an additional power folding mirror motor. The DDM sends a GMLAN serial data message to the passenger door module (PDM) when the power folding mirror switch is activated to the retract or extend positions. When the power folding switch is activated to the fold position, the DDM and PDM respond by applying battery voltage and ground to there respective power folding mirror control circuits in order to retract the mirrors. When the switch is activated to unfold the mirrors, the DDM and PDM reverse the polarity of the voltage and ground applied to the motors in order to move both mirrors to the fully extended position. For more detailed information concerning power mirror operation refer to Outside Mirror Description and Operation .

Reference Information

Schematic Reference

Outside Rearview Mirror Schematics

Connector End View Reference

Mirror Connector End Views

Electrical Information Reference

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

Scan Tool Reference

    •  Scan Tool Data Definitions
    •  Scan Tool Data List
    •  Scan Tool Output Controls

Circuit/System Testing

Power Folding Mirrors Malfunction

  1. Ignition ON, verify with a scan tool the mirror fold switch parameter changes as the switch is activated. The scan tool should change between EXTEND and RETRACT.
  2. If the function does not perform as specified, replace the DDM.
  3. Ignition OFF, disconnect the C4 harness connector at the inoperative folding mirror.
  4. Ignition OFF, test for less than 1.0 ohm of resistance between the control circuit terminal 1 and ground.
  5. If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the appropriate door control module.
  6. Ignition OFF, test for less than 1.0 ohm of resistance between the control circuit terminal 2 and ground.
  7. If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the appropriate door control module.
  8. Connect a test lamp between control circuit terminal 1 and control circuit terminal 2.
  9. Command the mirrors to the extend and retract positions with a scan tool. The test lamp should turn ON when commanding the EXTEND and RETRACT states.
  10. If the test lamp remains OFF during either of the commands, test for a short to ground on either control circuit. If the circuit tests normal, replace the appropriate door control module.
  11. If all circuits test normal, test or replace the inoperative outside rearview mirror.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Power Mirror Replacement
    •  Control Module References for DDM or PDM replacement, setup, and programming