Operation

OPERATION

The park brake switch is a normally closed, mechanically actuated leaf contact switch that is operated by the park brake lever mechanism. The switch is grounded through its mounting to the park brake lever mechanism and provides a ground input to the Body Control Module (BCM) (also known as the Signal Acquisition and Actuation Module/SAM) on a park brake switch sense circuit whenever the park brake is applied, and opens this circuit whenever the park brake is released. The park brake switch sense input to the BCM is used for control of the park brake indicator and may also be used as a logic input for other electronic features in the vehicle.

The park brake switch as well as the hard wired inputs and outputs of the switch may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. However, conventional diagnostic methods will not prove conclusive in the diagnosis of the electronic controls and communication that provide some features related to park brake switch operation. Proper diagnosis of the BCM, the CAN data bus and the electronic communication related to park brake switch operation requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.