Parking Brake Switch - Operation

OPERATION

Both the foot-operated and the hand-operated park brake switch are normally closed, mechanically actuated leaf contact switches that are operated by the foot or hand park brake lever mechanism. The switch is grounded through its mounting to the park brake lever mechanism and provides a ground input to the Instrument Cluster (IC) (also known as the Common Instrument Cluster/CIC) 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 IC is used as an additional logic input by the IC for control of the 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 between other modules and devices that rely upon inputs from the park brake switch. The most reliable, efficient, and accurate means to diagnose the electronic controls and communication related to park brake switch operation requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.