Test B: DTC P1572 or DTC P1703 - Brake On/Off Circuit Failure

PINPOINT TEST B: DTC P1572 OR DTC P1703 - BRAKE ON/OFF CIRCUIT FAILURE

B1-B4:

B4-B6:

B6-B8:

B8-B10:

Normal Operation
When the brake pedal is applied, the smart junction box (SJB) sends a message to the powertrain control module (PCM) to deactivate the speed control if engaged.

The speed control deactivator switch receives voltage through circuit 1890 (RD). The switch removes voltage from circuit 535 (LB/RD) to the PCM when the brake pedal is applied firmly and passes the stoplamp switch trip point. This is a redundant signal to the PCM.

Possible Causes
- Fuse
- Circuit 1890 (RD) open
- Circuit 535 (LB/RD) open, or short to voltage
- Speed control deactivator switch
- Anti-lock brake system (ABS) module
- Bussed electrical center (BEC)
- SJB
- PCM