Description And Operation: Operation
If the Electric Park Brake (EPB) switch is actuated with the caliper removed from the caliper bracket and still connected electrically, the EPB motor will fully extend causing damage to the caliper piston. Disconnect and isolate the negative battery cable. If equipped with an Intelligent Battery Sensor (IBS), disconnect the IBS connector first before disconnecting the negative battery cable.
To remove the vehicle from Service Mode, press the EPB switch while also pressing the brake pedal.
For information on Service Mode and normal operating conditions. Refer to MODULE, ELECTRIC PARK BRAKE (EPBM), DESCRIPTION AND OPERATION .
The EPB must be retracted prior to removing the brake caliper assembly. This can be done in two ways:
- A diagnostic scan tool (Service Mode position)
- Through the radio touchscreen
ABS MODULE
Controls all EPB functions and communicates via Controller Are Network - Chassis (CAN-C) with other vehicle systems as required.
REAR BRAKE CALIPER
Conventional sliding caliper with an Electromechanical Motor Gear Unit to drive the piston during park brake mode. Once applied, 12V power is not required to maintain clamp load.
EPB SWITCH
Packaged in the integrated center stack to the lower right of the shifter knob. Push to apply; push to release. LED indicator and illumination. Switch is hardwired to the ESC module only.
INSTRUMENT CLUSTER
BRAKE warning lamp to indicate Park Brake is ON. EPB Fault lamp to indicate EPB fault. Communicates with EPB via CAN-C.
ELECTRIC PARKING BRAKE OPERATION
- EPB can be applied with ignition OFF.
- EPB cannot be released with ignition OFF.
- Brake pedal must be applied when releasing EPB.
- Switch is hardwired to ESC module. No bus communication is used between the switch and the ESC module.
- EPB switch has built in redundancy and failure detection software in the ESC module.
- EPB does not require 12V power to maintain clamp load.
- EPB can be used to secure the vehicle automatically (Safe Hold).
- Motor performance is continuously monitored by ESC module.
ELECTRIC PARKING BRAKE SELECTION
- Auto Park Brake mode is customer selectable via Touchscreen Display.
- Selection is latching through key cycles.
- Drive Away Release is always enabled allowing the driver to automatically release the park brake by stepping on the gas pedal.
- EPB Engaged is indicated by the traditional red BRAKE warning lamp.
- EPB Faults are displayed by a new EPB Fault Tell-Tale.
- Numerous EVIC Text Messages provide appropriate driver information regarding EPB status.
- EPB Fault lamp flashes continuously when in Service Mode.
- EPB Controller stores approximately 30 Diagnostic Trouble Codes (DTCs) to aid in system diagnosis and repair.
BRAKE SERVICE MODE
- The park brake actuator must be retracted in order to push the caliper piston back into the caliper housing for routine caliper/lining service.
- The standard in the industry is to require a diagnostic scan tool to communicate with the ESC module to accomplish actuator retraction.
- This vehicle has an industry first customer usable retraction method.
- The routine is accessible through the radio touchscreen as a customer selectable option.
- This option has built in fail safes to prevent unintended consequences.
- Service mode is also available through the diagnostic scan tool.
