For 1990-2009 cars

### 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.

### DTC Descriptors

DTC B0969 01: Rear Window Heating Switch Telltale Circuit High Voltage
DTC B0969 02: Rear Window Heating Switch Telltale Circuit Low Voltage

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Rear Defrost Relay B+ | 2 | 2 | -- | --
Rear Defrost Switch Signal | B3743 5A | 2 | 2 | --
Rear Defog Relay Control | B0283 00 | B0283 00 | B0283 00 | --
Rear Defog Indicator Control | B0969 02 | 3 | B0969 01 | --
Rear Defogger Grid Control | 2 | 2 | 1 | --
Rear Window Defogger Grid Ground | -- | 2 | 2 | --
1. Rear Defogger Always On 2. Rear Defogger Inoperative 3. Rear Defogger Indicator Inoperative

### Circuit/System Description

The instrument panel cluster (IPC) monitors the voltage level in the rear window defog indicator control circuit. The voltage level should be low while the rear window defog indicator is illuminated and the voltage will be near system voltage when the rear window defog indicator is not illuminated.

### Conditions for Running the DTC

Battery voltage must be between 9-16 volts.

### Conditions for Setting the DTC

#### B0969 01

The IPC detects a short to ground in the rear window defog indicator control circuit.

#### B0969 02

The IPC detects a short to voltage in the rear window defog indicator control circuit.

### Action Taken When the DTC Sets

#### B0969 01

The rear window defog indicator will be continuously illuminated.

#### B0969 02

The rear window defog indicator will be inoperative.

### Conditions for Clearing the DTC

• | The DTC will be current for as long as the fault is present.

• | When the fault is no longer present, the DTC will be a history DTC.

• | A history DTC will clear after 50 ignition cycles.

### Reference Information

#### Schematic Reference

Defogger Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Rear Window Defogger 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

Command the Rear Window Defog LED Test ON and OFF with the scan tool. The rear window defog indicator should turn ON and OFF when changing between the commanded states.

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the HVAC control assembly.
2. Ignition ON, command the Rear Window Defog LED Test OFF with a scan tool
3. Test for less than 1 volt between the control circuit terminal 13 and ground.

⇒ | If greater than the specified range, test the control circuit for a short to voltage. If the circuit tests normal, replace the IPC.

4. Command the Rear Window Defog LED Test ON with a scan tool.
5. Test for greater than 9 volts between the control circuit terminal 13 and ground.

⇒ | If less than the specified range, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the IPC.

6. If all circuits test normal, replace the HVAC control assembly.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for IPC replacement, setup, and programming