C028E

DTC C028E

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 C028E 05
- Park Brake Solenoid Actuator Current Sensor Circuit Short to Battery or Open Circuit

DTC C028E 08
- Park Brake Solenoid Actuator Current Sensor 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

* Ignition OFF, ACCESSORY, or RUN mode.

* Battery voltage is between 9 - 16 V

Conditions for Setting the DTC

The parking brake control module detects an internal park brake current sensor malfunction.

Action Taken When the DTC Sets

* The parking brake will apply very slowly to avoid wheel lock up.

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

Conditions for Clearing the DTC

* The parking brake control module will clear the DTC after 40 consecutive ignition on/off cycles with at least one test pass in each ignition cycle and no test fail result.

* 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 Fuel Pump and Level Sensor Assembly

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 Control Module References for scan tool information

Circuit/System Verification

1. Ignition ON.

2. Verify no additional DTCs are set in other control modules.

• If additional DTCs are set
Refer to Diagnostic Trouble Code (DTC) List - Vehicle Diagnostic Trouble Code (DTC) List - Vehicle.

• If no additional DTCs are set

3. Verify DTC C028E is not set.

• If the DTC is set
Refer to Circuit/System Testing.

• If the DTC is not set

4. All OK.

Circuit/System Testing

1. Ignition OFF and all vehicle systems OFF, disconnect the harness at the K83 parking brake control module. It may take up to 2 minutes for all vehicle systems to power down.

2. Test for less than 10 ohms between the ground circuit terminal H and ground.

• If 10 ohms or greater

1. Ignition OFF.

2. Test for less than 2 ohms in the ground circuit end to end.

• If 2 ohms or greater, repair the open high/resistance in the circuit.

• If less than 2 ohms, repair open high/resistance in the ground connection.

• If less than 10 ohms

3. Ignition ON.

4. Verify that a test lamp illuminates between the B+ circuit terminal A and ground.

• If the test lamp does not illuminate and the circuit fuse is good

1. Ignition OFF.

2. Test for less than 2 ohms in the B+ circuit end to end.

• If 2 ohms or greater, repair the open high/resistance in the circuit.

• If less than 2 ohms, verify the fuse is not open and there is voltage at the fuse.

• If the test lamp does not illuminate and the circuit fuse is open

1. Ignition OFF.

2. Test for infinite resistance between the B+ circuit and ground.

• If less than infinite resistance, repair the short to ground on the circuit.

• If the test lamp illuminates

5. Connect the harness connector at the K83 parking brake control module.

6. Verify the park brake cable is connected properly. Refer to Park Brake System Diagnosis Component Tests and General Diagnostics

• If park brake cable is not connected properly
Repair as necessary.

• If park brake cable is connected properly

7. Ignition ON. Apply and release the park brake.

8. Verify DTC C028E is not set.

• If the DTC set
Replace the K83 parking brake control module.

• If the DTC is not set

9. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the repair.

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