P1574 BUICK, CADILLAC, CHEVROLET, FORD, GMC: STOP LAMP SWITCH CIRCUIT
POST UPDATED IN February, 2023
P1574 BUICK, CADILLAC, CHEVROLET, FORD, GMC: STOP LAMP SWITCH CIRCUIT
The stop lamp switch circuit diagnostic test is performed when a sudden decrease in speed of a non-powered wheel is detected, and such a stop must be caused by the application of the brakes.
The speed of the non-drive wheel and the status of the stop lamp switch are provided to the Powertrain Control Module (PCM) via serial data from the EBCM (Electronic Brake Control Module).
If a 4.02 km/h or greater decrease in non-drive wheel speed occurs within 0.4 seconds and a TCC transition occurs without a brake light switch change, diagnostic code P1574 OBDII will be set.
The reasons for setting the P1574 OBD2 fault code are:
To troubleshoot DTC P1574 OBDII code you must do the following: