DTC 50: Stoplamp Switch Fault

STOPLAMP SWITCH FAULT





Circuit Description
When the brake pedal is pressed, the contacts on the brake light switch close to illuminate the brake lights. Battery voltage is also applied to terminal 14 of the electronic brake control module (EBCM), which signals the ABS controller that the brakes are applied and ABS may be needed. Without this, signals from a wheel speed sensor that may indicate the need for ABS intervention are questionable. When the brake pedal is not pressed, the EBCM terminal 14 is grounded through the stoplamps.

Diagnosis
This procedure will check whether there is no output or constant output from the stoplamp switch and will determine the cause as a faulty switch or a problem in the circuitry.

Cause(s)
- The ground connection or the positive connection at the EBCM has failed.
- There is an open, short to ground, or short to positive in the vehicle wiring.
- The stoplamp switch has failed.

Fail Action
The system records a DTC 50. ABS operation is not disabled.

Test Description
The number(s) below refer to step(s) on the diagnostic table.
13. This step begins the process of troubleshooting stoplamps that are always on.

Diagnostic Aids
Inspect the wiring and the connectors carefully and thoroughly. Failure to do so could result in misdiagnosis, causing part replacement with the reappearance of the malfunction.








DTC 50 - Brake Lamp Switch (BLS) Fault