For 1990-2009 cars

## Heated Mirrors Inoperative w/o DG6

### Diagnostic Instructions

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

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

• | Diagnostic Procedure Instructions provides an overview of each diagnostic category.

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Mirror Heating Element Control | B1640 02 | 1 | B1640 01 | --
Ground | -- | 1 | -- | --
1. Heated Mirror Malfunction

### 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

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Outside Mirror Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

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.

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 X1 (RPO W49) or X2 (RPO DNP) harness connector at the outside rearview mirror.
2. Wait 1 minute, test for less than 1.0 ohm 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 door 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, replace the door switch.

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

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Outside Rearview Mirror Glass Replacement

• | Control Module References for DDS or PDS replacement, setup, and programming

## Heated Mirrors Inoperative w/DG6

### Diagnostic Instructions

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

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach

• | Diagnostic Procedure Instructions provides an overview of each diagnostic category

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Mirror Heating Element Control | 1 | 1 | 1 | --
Ground | -- | 1 | -- | --
1. Heated Mirror Malfunction

### Circuit/System Description

The RR DEFOG relay supplies voltage to the outside rearview mirror heater elements based on the current state of the rear window defogger. The relay supplies B+ through the driver/passenger mirror heating element control circuit when a request is seen.

### Reference Information

#### 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

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

Control Module References for scan tool information

### Circuit/System Verification

1. Ignition ON, press the rear window defogger switch. Verify the rear window defogger turns ON and the rear window becomes warm.

⇒ | If the rear window defogger does not turn on, refer to 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. Ignition OFF, test for less than 5 ohms between the ground circuit terminal 3 and ground.

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

3. Connect a test lamp between the control circuit terminal 7 and ground.
4. Ignition ON, command the rear window defogger ON and OFF with the rear defogger switch. The test lamp should turn ON and OFF when changing between the commanded states.

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

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

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

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Outside Rearview Mirror Glass Replacement

• | Control Module References for DDS or PDS replacement, setup and programming