Pinpoint Test E : The Parking Brake Does Not Hold The Vehicle, Does Not Apply, Does Not Release Using The Parking Brake Switch Or Automatic Release Function: Notes
Refer to Vehicle Dynamic Systems for schematic and connector information.
Normal Operation and Fault Conditions
When the ABS module receives a parking brake apply or release request, the ABS module sends voltage to the parking brake actuator motors. The ABS module also monitors the current draw of the actuator motors to determine when the brake pads contact the brake disc, to determine when the appropriate amount of clamping force is being applied to the brake disc and to determine when the brake pads are retracted to their start position.
A HS-CAN issue or concern results in a failure to release the parking brake.
The ABS module runs self-tests before, during and after an apply or release request. These self-tests are done to determine parking brake system functionality. High actuator motor circuit resistance, a short to ground, a short to voltage, an open circuit, a mechanical or electrical failure of the actuator motor or an internal failure of the ABS module may cause one or more of these self-tests to fail resulting in the ABS module setting one or more Diagnostic Trouble Codes (DTCs).
The actuator motors have a serviceable jumper harness connecting the actuator motor to the body harness at C431 for the LH actuator motor and C432 for the RH actuator motor.
DTC Fault Trigger Conditions
| DTC | Description | Fault Trigger Conditions |
|---|---|---|
| B1111:4B | Electric Park Brake Enable: Over Temperature | This DTC sets due to excessive apply and release operations by the driver (more than 50 in an 8 minute period), a shorted or blocked actuator motor or a shorted motor circuit. |
| C2005:1B, C2006:1B | Right Actuator, Left Actuator: Circuit Resistance Above Threshold | This DTC sets in continuous memory and on-demand if during an apply (clamping) command, the measured resistance in the motor circuit is higher than a predetermined threshold. |
| C2005:71, C2006:71 | Right Actuator, Left Actuator: Actuator Stuck | This DTC sets in continuous memory and on-demand if during an apply or release command, the ABS module detects no movement of the actuator motor. |
| C2007:13, C2008:13 | Right Motor, Left Motor: Circuit Open | This DTC sets in continuous memory and on-demand if the ABS module detects a difference in the current between the positive side and the negative side of the actuator motor. |
| C2007:1C, C2008:1C | Right Motor, Left Motor: Circuit Voltage Out Of Range | This DTC sets in continuous memory and on-demand if the ABS module detects a short to ground or a short to voltage on the actuator motor circuits. |
| C2007:92, C2008:92 | Right Motor, Left Motor: Performance Or Incorrect Operation | This DTC sets in continuous memory and on-demand if the ABS module detects a current greater than 23 amps after an apply or release request, detects a mismatch in motor control (power instead of ground or ground instead of power), or detects a power loss that exceeds a predetermined threshold during an apply or release function. |
| C1A43:98 | Motor Supply: Component or System Over Temperature | This DTC sets when the temperature of the ABS module Field Effect Transistor (FET) reaches a preset limit. This is most likely caused by excessive resistance in the actuator motor wiring or excessive resistance in the actuator motor. |
Possible Sources
- Automatic release functional requirements not met
- BCM concern
- PCM concern
- Wiring, terminals or connectors
- Brake caliper
- Parking brake actuator motor
- ABS module