Heated Mirrors Inoperative

Heated Mirrors Inoperative

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.

Circuit/System Description

The driver door switch (DDS) and passenger door switch (PDS) supply voltage to the outside rearview mirror heater elements upon receipt of a serial data message from the HVAC module indicating that the rear defrost system is active. The door switch supplies B+ through the driver/passenger mirror heating element supply voltage circuit when a request is seen. Ground is applied through the driver/passenger mirror heating low reference circuit.

Diagnostic Aids

The automatic day-night feature of the inside rearview mirror may mot operate properly or become inoperative due to a short to battery positive voltage in the backup lighting system.

Reference Information
Schematic Reference

Outside Rearview Mirror Schematics (Outside Rearview Mirror Schematics)
Connector End View Reference

Component Connector End Views (Component Connector End Views)
Description and Operation

Outside Mirror Description and Operation (Heated Mirrors) (Outside Mirror Description and Operation (Heated Mirrors))Outside Mirror Description and Operation (Power Mirrors) (Outside Mirror Description and Operation (Power Mirrors))
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.

2. Rear window defogger ON, verify both the left and right outside mirror glass become warm.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector X3 at the appropriate door module.
2. Ignition ON, verify a test lamp does not illuminate between the supply voltage circuit terminal B7 and ground.

• If the test lamp illuminates, test the supply voltage circuit for a short to voltage.

3. Ignition OFF, test for infinite resistance between the supply voltage circuit terminal B7 and ground.

• If less than the specified value, test the supply voltage circuit for a short to ground. If the circuit tests normal, test or replace the applicable rearview mirror face.

4. Test for 5-10 ohms of resistance between the supply voltage circuit terminal B7 and the low reference circuit terminal B3.

• If not within the specified range, test the supply voltage circuit and the low reference circuit for an open/high resistance. If the circuits test normal, test or replace the appropriate rearview mirror face.

5. If all circuits test normal, replace the appropriate door module.

Repair Instructions

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

* Outside Rearview Mirror Glass Replacement (Outside Rearview Mirror Glass Replacement)
* Control Module References (Control Module References)for DDM or FPDM replacement, setup and programming