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

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

Normal Operation
Fused battery voltage is sent from the central junction box (CJB) fuse 14 (20A) through circuit 1119 (RD) to the brake pedal position switch. When the brake pedal is depressed, voltage is supplied to the CJB fuse 28 (7.5A) through circuit 511(LG) and then to the ABS module through circuit 1651 (WH/RD). The ABS module sends the brake pedal position to the PCM over the high speed controller area network (HS-CAN) bus lines interrupting the speed control. The speed control deactivator switch interrupts the power signal to the PCM through circuit 636 (OG) when the brake pedal is applied firmly. This is a redundant signal to the PCM.
- DTC P1572 (Brake Pedal Switch Circuit) - sets when the PCM does not sense the proper sequence of the brake pedal input signal from both the stoplamp and deactivator switches when the brake pedal is pressed and released.
- DTC P1703 (Brake Switch Out of Self-Test Range) - sets when there is an open or short in the deactivator switch circuits or when there is an open or short in the stoplamp circuits.

This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Speed control deactivator switch
- PCM

B1-B4:

B4-B6:

B7: