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 Descriptors

DTC B1722 01: Mirror Power Fold Control Circuit Short to Battery

DTC B1722 02: Mirror Power Fold Control Circuit Short to Ground

DTC B1722 04: Mirror Power Fold Control Circuit Open

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Folding Mirror Motor Retract Control

B1722 02

1

B1722 01

--

Folding Mirror Motor Extend Control

B1722 02

1

B1722 01

--

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 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.

Conditions for Running the DTC

Battery voltage must be between 9-16 volts.

Conditions for Setting the DTC

An improper voltage level is seen on either the folding mirror motor retract control circuit or the folding mirror motor extend control circuit.

Actions Taken When the DTC Sets

The power folding mirror function will be disabled.

Conditions for Clearing the DTC

    • A current DTC will clear when the fault is no longer present.
    • A history DTC will clear after 40 fault free ignition cycles.

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

Ignition ON, using the folding mirror switch, the left and right rearview mirrors should extend and retract as commanded.

Circuit/System Testing

Driver

  1. Ignition OFF, disconnect the X1 harness connector at the outside rearview mirror.
  2. Connect a test lamp between control circuit terminal 1 and control circuit terminal 2.
  3. Command the mirror Fold to Retract and extend with a scan tool. The test lamp should turn ON when commanding the retract and extend states.
  4. If the test lamp remains OFF during either of the commands, test for a short to voltage, short to ground, or an open/high resistance on either control circuit. If the circuits test normal, replace the DDM.
  5. If all circuits test normal, test or replace the outside rearview mirror.

Passenger

  1. Ignition OFF, disconnect the harness connector at the outside rearview mirror.
  2. Connect a test lamp between control circuit terminal 4 and control circuit terminal 5.
  3. Command the mirror fold to retract and extend with a scan tool. The test lamp should turn ON when commanding the retract and extend states.
  4. If the test lamp remains OFF during either of the commands, test for a short to voltage, short to ground, or an open/high resistance on either control circuit. If the circuits test normal, replace the PDM.
  5. If all circuits test normal, test or replace the 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