Brake Light Switch: Testing and Inspection

DIAGNOSIS AND TESTING - STOP LAMP SWITCH

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.





1. Using a scan tool, check for Diagnostic Trouble Codes (DTCs) in the BCM and PCM. If no DTCs are found, go to Step 2. If any DTCs are found, repair as needed.

1. Monitor the Brake Lamp Switch operation by using the diagnostic scan tool to verify that both switch states in the BCM changes while actuating the brake pedal. If actuation is detected in the BCM, move to the PCM to confirm actuation is detected.

1. Disconnect and isolate the battery negative cable.

2. Disconnect the instrument panel wire harness connector from the brake lamp switch.

3. Using an ohmmeter, perform the continuity tests at the terminal pins (1) in the brake lamp switch connector receptacle as shown in the Brake Lamp Switch Tests table.





4. If the switch fails any of the continuity tests, replace the ineffective brake lamp switch as required.