Pinpoint Test E : The Parking Brake Does Not Hold The Vehicle, Does Not Apply, Does Not Release Using The Parking Brake Switch: Notes
Refer to Vehicle Dynamic Systems for schematic and connector information.
Normal Operation and Fault Conditions
When the EPB module receives a parking brake apply or release request, the EPB module sends voltage to the parking brake actuator motors. The EPB 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 results in a failure to release the parking brake.
The EPB 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 EPB module causes one or more of these self-tests to fail resulting in the EPB module setting one or more Diagnostic Trouble Codes (DTCs).
DTC Fault Trigger Conditions
| DTC | Description | Fault Trigger Conditions |
|---|---|---|
| C2007:01, C2008:01 | Right Motor, Left Motor: General Electrical Failure | During an apply or release command, the EPB module expects to see voltage sent out to the motor and return from the motor. This DTC sets in continuous memory and on-demand if the EPB module does not detect the voltage on both motor circuits. |
| C2007:11, C2008:11 | Right Motor, Left Motor: Circuit Short to Ground | This DTC sets in continuous memory and on-demand if during an apply or release command if the EPB module detects a short to ground on either of the 2 motor circuits. |
| C2007:12, C2008:12 | Right Motor, Left Motor: Circuit Short to Battery | This DTC sets in continuous memory and on-demand if the EPB module detects a short to battery on either of the 2 motor circuits while the parking brake system is not being applied or released. |
| C2007:18, C2008:18 | Right Motor, Left Motor: Circuit Current Below Threshold | This DTC sets in continuous memory and on-demand if the EPB module detects lower than expected current draw during an apply or release command. |
| C2007:19, C2008:19 | Right Motor, Left Motor: Circuit Current Above Threshold | This DTC sets in continuous memory and on-demand if the EPB module detects higher than expected current draw during an apply or release command. |
Possible Sources
- Fuse
- Wiring, terminals or connectors
- Parking brake actuator motor
- Brake caliper
- EPB module