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 provide an overview of each diagnostic category.

### DTC Descriptors

DTC C0298 00: Park Brake Unlatch Switch Circuit Malfunction

### Circuit/System Description

The electric parking brake control module has an internal motor, apply actuator, release actuator, and temperature sensor. The electric parking brake control module also contains the logic for applying and releasing the parking brake when commanded by the electric parking brake switch. When the electric parking brake control module receives a signal from the switch the internal circuit board temperature is checked to verify it is within operating range before the control module performs the requested operation.

### Conditions for Running the DTC

Ignition OFF, ACCESSORY, or RUN mode.

### Conditions for Setting the DTC

The electric parking brake control module detects the apply or release button was activated for more than 90 seconds.

### Action Taken When the DTC Sets

A message and/or a warning indicator may be displayed.

### Conditions for Clearing the DTC

• | The electric parking brake control module clears the history DTC when a current DTC is not detected in 40 ignition cycles.

• | The condition for the DTC is no longer present.

• | The electric parking brake switch button is released using the scan tool.

### Diagnostic Aids

Check if the electric parking brake switch is stuck in the apply or release position which may cause the DTC to set.

### Reference Information

#### Schematic Reference

Park Brake System Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Electronic Parking Brake Control Module Description

#### 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. Verify DTC C0293 is not set.

⇒ | If DTC C0293 is set, refer to DTC C0293.

2. Command the Park Brake Switch to Released with a scan tool. The BRAKE light should turn off and the Park Brake Status on the scan tool should display Released.

⇒ | If the BRAKE light does not turn off or the Park Brake Status does not display Released replace the S91 Electric Parking Brake Switch.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for electric parking brake control module replacement, setup, and programming