Important: Use care when performing service operations on or around park brake cables. Damage to the plastic coating will reduce corrosion protection and if the damaged area passes through the seal, increased park brake effort could result. Contacting the coating with sharp-edged tools, or with sharp surfaces of the vehicle underbody, should be avoided.
The park brake system is a mechanical and electrical system which operates on the rear disc brakes. The system is activated by depressing a foot pedal lever assembly, which sets the rear brake caliper via cables. The park brake is released by shifting the vehicle out of park or activating the manual release.
Park Brake Set
The park brake can be set only when the gear shift lever is in Park or Neutral. The body control module (BCM) deactivates both park brake release solenoids and the park brake can be set.
Park Brake Release
The body control module (BCM) controls the operation of the electric release park brake. The BCM uses serial data messages to determine if the correct conditions exist to release the park brake. The park brake is released under the following conditions:
| • | The engine is ON. |
| • | The gear shift lever is not in Park or Neutral. |
| • | The park brake switch is closed. |
When all of the above conditions exist, the BCM releases the park brake by simultaneously activating the 2 park brake solenoids. After 2 seconds, the BCM deactivates solenoid A. The BCM continues to activate solenoid B while the above conditions exist, which prevents the park brake from being set.
Brake System Indicators
Reference numbers are used in conjunction with a DIC warning message on export vehicles only.
BRAKE
The IPC illuminates the BRAKE indicator and sends a serial data message in order to activate an audible warning when the following occurs:
| • | The IPC detects that the park is applied signal circuit is low. |
| • | The IPC detects a low brake fluid condition signal circuit is low. |
| • | The electronic brake control module (EBCM) detects a malfunction with the antilock brake system. The IPC receives a serial data message from the EBCM requesting illumination. |
| • | The IPC detects a loss of communications with the EBCM and the discrete back-up ABS indicator signal is open. |
| • | The IPC performs the displays test at the start of each ignition cycle. The indicator illuminates for approximately 3 seconds. |
CHECK BRAKE FLUID - 37
The IPC illuminates the CHECK BRAKE FLUID -- 37 indicator in the DIC and sends a serial data message in order to activate an audible warning when the IPC detects that the brake fluid level is below the normal operating range.
