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

B1722 02

B1722 04

B1722 01

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Folding Mirror Motor Extend Control

B1722 02

B1722 04

B1722 01

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Circuit/System Description

The Driver Door Module (DDM) and Passenger Door Module (PDM) control the power folding or power extending functions of the outside rearview mirrors. The folding mirror motors are controlled by using bi-directional motor controls through the folding mirror motor retract control circuit and the folding mirror motor extend control circuit.

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 References

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 Idle, Extend, and Retract.
  2. If the parameter does not cycle between the specified values, replace the DDM.
  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 X7 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 1
    • Control circuit terminal 2
    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 1
    • Control circuit terminal 2
    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 5-40 ohms between the control circuit terminal 1 and the control circuit terminal 2.
  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 door module.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

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