Normal Operation
WARNING: This page is about a different car, the 2009 Ford Mustang. However, it is still accessible from the selected car via links, so may be relevant.
When the brake pedal is applied, the smart junction box (SJB) sends a message to the PCM to deactivate the speed control if engaged.
The speed control deactivator switch receives voltage through circuit 391 (RD/YE). 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.
- DTC P1703 (Brake On/Off Circuit Failure) - 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:
- Fuse
- Wiring, terminals or connectors
- Speed control deactivator switch
- ABS module
- Bussed electrical center (BEC)
- SJB
- PCM