Ignition voltage is supplied to the heated mirror relay and switch from the IP fuse block. When the heated mirror switch is pressed, ignition voltage is supplied to the relay coil energizing the relay. Once the relay has been energized it will remain energized for the entire ignition cycle through the switch side of the relay by the heater element control circuit. Each outside rearview mirror has a positive temperature coefficient (PTC) thermistor in series with heating element that is connected to a constant ground source. The resistance of the PTC will vary with the temperature of the mirror face to maintain a constant mirror temperature.

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

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON, command the heated outside rearview mirrors ON by pressing the outside heated mirror switch. The outside rearview mirror heater elements and the heated mirror indicator should turn ON.
2. Ignition OFF, the outside rearview mirror heat elements and the heated mirror indicator should turn OFF.

Outside Heated Mirror Malfunction

1. Ignition OFF, disconnect the HTD MIR relay.
2. Test for less than 10 ohms between the ground circuit terminal F85 and ground.

⇒	If greater than the specified range, test the ground circuit for an open/high resistance.

3. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal F87 and ground.

⇒	If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.

4. Connect a test lamp between the relay control circuit terminal F86 and ground.
5. Press and release the outside heated mirror switch. The test lamp should turn ON and OFF.

⇒	If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, test or replace the outside heated mirror switch.

⇒	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, test or replace the outside heated mirror switch.

6. Connect a test lamp between the heated mirror control circuit terminal F30 and ground.
7. Press and release the outside heated mirror switch. The test lamp should turn ON and OFF.

⇒	If the test lamp is always ON, test the control circuit for a short to voltage.

⇒	If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance.

8. Ignition OFF, connect the HTD MIR relay and disconnect the harness connector at the appropriate outside rearview mirror.
9. Test for less than 10 ohms between the outside rearview mirror ground circuit terminal A and ground.

⇒	If greater than the specified range, test the ground circuit for an open/high resistance.

10. Connect a test lamp between the control circuit terminal H and ground.
11. Ignition ON, command the outside rearview mirror heating element ON by pressing the outside heated mirror switch, the test lamp should illuminate.

⇒	If the test lamp does not illuminate, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the HTD MIR relay.

12. Ignition OFF, the test lamp should turn OFF.

⇒	If the test lamp remains illuminated, test the control circuit for a short voltage.

13. If all circuits test normal, replace the outside rearview mirror.

Heated Mirror Indicator Malfunction

1. Ignition OFF, disconnect the harness connector at the outside heated mirror switch.
2. Test for less than 10 ohms between the outside heated mirror switch ground circuit terminal F and ground.

⇒	If greater than the specified range, test the ground circuit for an open/high resistance.

3. Test for less than 200 ohms between the indicator control circuit terminal D and ground.

⇒	If greater than the specified range, test the control circuit for an open/high resistance.

4. If all circuits test normal, replace the heated mirror switch.

Relay Test

1. Ignition OFF, disconnect the HTD MIR relay.
2. Test for 60-180 ohms between terminals 85 and 86.

⇒	If the resistance is not within the specified range, replace the relay.

3. Test for infinite resistance between the following terminals:

•

30 and 86

•

30 and 87

•

30 and 85

•

85 and 87

⇒	If not the specified value, replace the relay.

4. Install a 15-amp fused jumper wire between relay terminal 85 and 12 volts. Install a jumper wire between relay terminal 86 and ground. Test for less than 2 ohms between terminals 30 and 87.

⇒	If greater than the specified range, replace the relay.

Outside Heated Mirror Switch

1. Ignition OFF, disconnect the harness connector at the outside heated mirror switch.
2. Test for infinite resistance between the control circuit terminal C and the B+ terminal A with the switch in the open position.

⇒	If not the specified value, replace the outside heated mirror switch.

3. Test for less than 5 ohms between the control circuit terminal C and the B+ terminal A with the switch in the closed position.

⇒	If greater than the specified range, replace outside heated mirror switch.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.