Brake Warning Indicator: Testing and Inspection

BRAKE INDICATOR

WARNING: To avoid serious or fatal injury on vehicles equipped with airbags, disable the Supplemental Restraint System (SRS) before attempting any steering wheel, steering column, airbag, seat belt tensioner, impact sensor, or instrument panel component diagnosis or service. Disconnect and isolate the battery negative (ground) cable, then wait two minutes for the system capacitor to discharge before performing further diagnosis or service. This is the only sure way to disable the SRS. Failure to take the proper precautions could result in accidental airbag deployment.

The hardwired park brake switch input to the instrument cluster, also known as the Cab Compartment Node (CCN) may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. The wiring information includes wiring diagrams, proper wire and connector repair procedures, details of wire harness routing and retention, connector pin-out information and location views for the various wire harness connectors, splices and grounds.

However, conventional diagnostic methods may not prove conclusive in the diagnosis of the CCN, the Antilock Brake Module (ABM), the Controller Area Network (CAN) data bus, or the electronic message inputs also used by the CCN to provide brake indicator operation. The most reliable, efficient, and accurate means to diagnose the CCN, the ABM, the CAN data bus or the electronic communication related to brake indicator operation requires the use of a diagnostic scan tool. Perform the appropriate diagnostic procedures as needed.