Heated Mirrors Malfunction

Heated Mirrors Malfunction

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.

* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Diagnostic Fault Information






Circuit/System Description

The outside rearview mirrors heat during the defrost/defog cycles for the rear window. The driver door module (DDM) and passenger door module (PDM) control the heated mirror functions. When the door modules receive a message from the HVAC control module indicating the rear defogger has been turned ON, both door modules will activate the heated mirror by applying voltage to the heated mirror element control circuit.

Reference Information

Schematic Reference

Outside Rearview Mirror Schematics Outside Rearview Mirror Schematics

Connector End View Reference

Component Connector End Views 5 Bow Lowered Switch (CM7)

Description and Operation

Outside Mirror Description and Operation Outside Mirror

Electrical Information Reference

* Circuit Testing Circuit Testing

* Connector Repairs Connector Repairs

* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections

* Wiring Repairs Wiring Repairs

Scan Tool Reference

Control Module References Control Module References for scan tool information

Circuit/System Verification

1. Ignition ON, press the rear window defogger switch. Verify the rear window defogger indicator illuminates.

• If the rear window defogger indicator does not illuminate, refer to Rear Window Defogger Malfunction Rear Window Defogger Malfunction.

2. Verify both the left and right outside mirror glass become warm.

Circuit/System Testing

1. Ignition OFF, disconnect the X1 harness connector at the apporpriate outside rearview mirror.

2. Verify that a test lamp iluminates between B+ and the ground circuit terminal B.

• If the test lamp does not illuminate, test the ground circuit for an open/high resistance.

3. Connect a test lamp between the control circuit terminal E and the ground circuit terminal B.

4. Command the mirror heater ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.

• If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the door control module.

• If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the door control module.

5. If all circuits test normal, test or replace the outside rearview mirror glass.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.

* Outside Rearview Mirror Glass Replacement (Except North American) Outside Rearview Mirror Glass Replacement (Except North American)Outside Rearview Mirror Glass Replacement (North American) Outside Rearview Mirror Glass Replacement (North American)

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