Service Information

Volt

DTC C028A

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 C028A 01: Hand brake Motor Circuit Short to Battery

DTC C028A 02: Hand brake Motor Circuit Short to Ground

DTC C028A 04: Hand Brake Motor Circuit Open Circuit

DTC C028A 08: Hand brake Motor Circuit Performance-Signal Invalid

DTC C028A 28: Hand brake Motor Circuit Performance-Incorrect Frequency

Circuit/System Description

The hand brake control module has an internal motor, apply actuator, release actuator, and temperature sensor. The hand brake control module also contains the logic for applying and releasing the hand brake when commanded by the hand brake switch. When the hand 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 hand brake control module will also diagnose the internal hand brake motor circuit to verify it is functioning properly. The hand brake motor circuit is used to command motor operation, apply and release tension on the hand brake cable, which will apply and release the hand brake.

The hand brake will self diagnose the internal Hand brake Motor Circuit. This circuit is used to drive the motor, which pulls on the hand brake cable, ultimately applying and releasing the hand brake.

Conditions for Running the DTC

•	Ignition OFF, ACCESSORY, or RUN mode.

•	Battery voltage is between 9 -16V

Conditions for Setting the DTC

The hand brake control module detects an internal motor malfunction.

Action Taken When the DTC Sets

•	The electric hand brake is disabled.

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

Conditions for Clearing the DTC

•	The hand 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

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

Verify that DTC C028A is not set.

⇒	If DTC is set, program the hand brake control module. If the DTC resets, replace the K83 Hand brake Control Module.

Repair Instructions

Perform the Diagnostic Repair Verification

•	Electronic Hand brake Control Module Replacement

•	Control Module References