C028A

DTC C028A, C028B, or C028F

Diagnostic Instructions

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

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

* Diagnostic Procedure Instructions 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

DTC C028B 08
- Park Brake Motor Position Sensor Signal Performance-Signal Invalid

DTC C028B 26
- Park Brake Motor Position Sensor Signal Low Frequency

DTC C028B 29
- Park Brake Motor Position Sensor Signal Too Few Pulses

DTC C028B 2A
- Park Brake Motor Position Sensor Signal Too Many Pulses

DTC C028F 01
- Park Brake Solenoid Actuator Circuit Short to Battery

DTC C028F 02
- Park Brake Solenoid Actuator Circuit Short to Ground

DTC C028F 08
- Park Brake Solenoid Actuator Circuit Performance-Signal Invalid

Circuit/System Description

The parking brake control module has an internal motor, apply actuator, release actuator, and temperature sensor. The parking brake control module also contains the logic for applying and releasing the parking brake when commanded by the park brake switch. When the 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.

The parking brake control module will diagnose the internal park brake motor circuit to verify it is functioning properly. The park brake motor circuit is used to command motor operation, apply and release tension on the parking brake cable, which will apply and release the parking brake. The park brake will self diagnose the internal Park Brake Motor Circuit. This circuit is used to drive the motor, which pulls on the park brake cable, ultimately applying and releasing the park brake.

The parking brake control module contains an internal park brake motor position sensor which monitors the park brake motor position. When the 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.

The parking brake control module contains an internal park brake solenoid actuator, and performs diagnostics on the solenoid actuator circuitry to verify it is functioning properly.

Conditions for Running the DTC

* Vehicle OFF, Vehicle in Service Mode, Vehicle ON, or Engine Running.

* Battery voltage is between 9 - 16 V

Conditions for Setting the DTC

DTC C028A

The parking brake control module detects an internal motor malfunction.

DTC C028B

The parking brake control module detects an internal motor position sensor signal malfunction.

DTC C028F

The parking brake control module detects an internal park brake solenoid malfunction.

Action Taken When the DTC Sets

DTC C028A

* The parking brake is disabled.

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

DTC C028B

* The parking brake is disabled, one release allowed.

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

DTC C028F

* The parking brake is disabled, one release allowed.

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

Conditions for Clearing the DTC

* The parking brake control module clears the history DTC when a current DTC is not detected in 40 consecutive drive cycles.

* Calibrate the parking brake control module.

* The condition for the DTC is no longer present.

Reference Information

Schematic Reference

Park Brake System Schematics [1][2]Electrical Diagrams

Connector End View Reference

Component Connector End Views Hybrid/EV Battery Pack X1

Description and Operation

Electronic Parking Brake Control Module Description Description and Operation

Electrical Information Reference

* Circuit Testing Circuit Testing

* Connector Repairs Connector Repairs

* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections

* Wiring Repairs Wiring Repairs

Scan Tool Reference

Control Module References Programming and Relearning for scan tool information

Circuit/System Verification

1. Vehicle in service mode.

2. Verify that DTC C028A, C028B, or C028F is not set.

• If any of the DTCs are set

1. Perform the Park Brake Motor Reset procedure with a scan tool.

2. Vehicle in service mode. Apply and release the park brake.

3. Verify the DTC is not set.

• If the DTC is set,
replace the K83 parking brake control module.

• If the DTC is not set

4. All OK.

• If none of the DTC are set

3. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.

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