Heated Mirrors Malfunction (with DS3 and W49)
Heated Mirrors Malfunction (with DS3 and W49)
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 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 control module indicating that the rear defrost system is active. The door module supplies B+ through the driver/passenger mirror heating element control circuit when a request is seen. Ground is applied through the driver/passenger mirror heating element ground circuit.
Reference Information
Schematic Reference
Outside Rearview Mirror Schematics Outside Rearview Mirror Schematics
Connector End View Reference
Component Connector End Views A/C Compressor Clutch
Description and Operation
Outside Mirror Description and Operation (Power Mirrors) Outside Mirror (Power Mirrors)Outside Mirror Description and Operation (Heated Mirrors) Outside Mirror (Heated 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, refer to Rear Window Defogger Malfunction Rear Window Defogger Malfunction.
2. Press the rear window defogger switch. Verify both the left and right outside mirror glass become warm.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the outside rearview mirror.
2. Wait 1 minute, test for less than 10ohms between the ground circuit terminal 3 and ground.
• If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the appropriate door switch.
3. Connect a test lamp between the control circuit terminal 7 and ground.
4. Ignition ON, 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 DDS.
• 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 PDS.
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 Outside Rearview Mirror Glass Replacement
* Control Module References Control Module References for DDS or PDS replacement, setup, and programming