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 provides an overview of each diagnostic category. |
DTC Descriptor
DTC C0291 02: Park Brake Release Relay Circuit Short to GroundDTC C0291 05: Park Brake Release Relay Circuit Short to Battery or Open
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Park Brake Relay Coil 1 Control Circuit | C0291 02 | C0291 05 | C0291 05 | -- |
Park Brake Release Relay Ground Circuit | -- | C0291 05 | C0291 05 | -- |
Circuit/System Description
The park brake system uses a pair of solenoids to set or release the park brake pedal. These solenoids are powered by relays which are commanded ON and OFF by the body control module (BCM). When the gear shift lever is taken out of Park or Neutral, the BCM simultaneously activates both solenoids to release the park brake pedal. The release solenoid is deactivated after 2 seconds and The Release solenoid remains activated until the gear shift lever is in Park or Neutral, the engine is OFF, and the park brake switch is closed.
Conditions for Running the DTC
| • | The ignition is ON. |
| • | The ignition voltage is greater than 8 volts. |
Conditions for Setting the DTC
The BCM detects the park brake relay coil 1 control circuit is shorted to ground, voltage, or open.
Action Taken When the DTC Sets
The ABS indicator turns ON.
Conditions for Clearing the DTC
| • | The condition for setting the DTC is no longer present. |
| • | The body control module (BCM) automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles |
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Park Brake System Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
- Apply the park brake. Verify that the park brake remains applied.
- Start the engine, and shift the transmission into Drive. Verify that the park brake releases.
Circuit/System Testing
Caution: Chock the wheels to prevent the vehicle from moving. Failure to chock the wheels can cause personal injury when the electrical system is repaired.
- Remove the park brake release relay from the I/P relay block. Test the relay coil ground circuit terminal C1 for an open. Verify that there is continuity between terminal C1 and ground.
- Ignition ON. Probe terminal C2 with a test lamp that is connected to ground. Command Park Brake Solenoid Relay A ON with a scan tool, in Body, Body Control Module, Special Functions, Miscellaneous Test. Verify that the test lamp illuminates.
- Command Park Brake Solenoid Relay A OFF with the scan tool. Verify that the test lamp turns OFF.
- Replace the park brake release relay.
| ⇒ | If the circuit is open, repair the circuit. |
| ⇒ | If the test lamp does not illuminate, test the control circuit for an open or a short to ground. If OK, replace the BCM. |
| ⇒ | If the test lamp remains illuminated, test the control circuit for a short to voltage. If OK, replace the BCM. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for BCM replacement, setup, and programming |
