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.

Schematic Reference

Outside Rearview Mirror Schematics

Connector End View Reference

Mirror Connector End Views

Description and Operation

Outside Mirror Description and Operation

Electrical Information Reference

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 Inoperative .

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

1. Ignition OFF, disconnect the harness connector C3 at the appropriate door switch.
2. Ignition ON, verify a test lamp does not illuminate between the supply voltage circuit terminal 7 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 7 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 7 and the low reference circuit terminal 3.

⇒	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, test or replace the appropriate door switch.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.