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.

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Folding Mirror Motor Retract Control

1

1

1

--

Folding Mirror Motor Extend Control

1

1

1

--

1. Power folding mirror inoperative

Circuit/System Description

This feature allows the operator to simultaneously retract both mirrors to a fully folded position. The driver door switch assembly (DDSA) contains the power folding mirrors switch and, each mirror contains an additional power folding mirror motor. The DDSA sends a message to the DDM and PDM when the power folding mirror switch is activated to the retract or extend positions. When the door modules detect an active power folding mirror command from the DDSA, the DDM and PDM each apply battery voltage and ground to the appropriate circuits of their respective power folding motor in order to retract the mirrors. When the switch is activated to unfold the mirrors, the door modules reverse the polarity of the voltage and ground applied to the reversible folding motors to move both mirrors to the fully extended position.

Reference Information

Schematic Reference

Outside Rearview Mirror Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Outside Mirror 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

  1. Ignition ON, observe the scan tool Mirror Fold Switch parameter while cycling the mirror fold switch between the extend and retract positions. The parameter should change between Active and Inactive.
  2. If the parameter does not cycle between the specified values, replace the DDSA.
  3. Command the power folding mirrors to extend and retract using the mirror fold switch. Both mirrors should extend and retract as commanded.

Circuit/System Testing

  1. Ignition OFF, disconnect the X4 harness connector at the appropriate door module.
  2. Ignition ON, verify a test lamp does not illuminate between the following circuit terminals and ground:
  3. • Control circuit terminal 3
    • Control circuit terminal 4
    If the test lamp illuminates, test the appropriate circuit for a short to voltage.
  4. Ignition OFF, test for infinite resistance between the following circuits and ground:
  5. • Control circuit terminal 3
    • Control circuit terminal 4
    If less than the specified value, test the appropriate circuit for a short to ground. If the circuits test normal, test or replace the rearview mirror.
  6. Test for 5-25 ohms between the control circuit terminal 3 and the control circuit terminal 4.
  7. If not within the specified range, test both control circuits for an open/high resistance. If the circuits test normal, test or replace the rearview mirror.
  8. If all circuits test normal, replace the appropriate door module.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Outside Rearview Mirror Replacement
    •  Control Module References for DDSA, DDM, and PDM replacement, setup, and programming