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 C028A 01: Park Brake Motor Circuit Short to Battery
DTC C028A 02: Park Brake Motor Circuit Short to Ground
DTC C028A 04: Park Brake Motor Circuit Open Circuit
DTC C028A 08: Park Brake Motor Circuit Performance-Signal Invalid
DTC C028A 28: Park Brake Motor Circuit Performance-Incorrect Frequency

### 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 an internal motor malfunction.

### Action Taken When the DTC Sets

• | The electric parking brake is disabled.

• | 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.

### 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

Remove the EPB fuse and reinstall. Verify DTC C028A is not set.

⇒ | If DTC is set, replace the K83 Electric Parking Brake Control Module.

### 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.