Brake Switch Feedback
WARNING: This page is about a different car, the 2003 Pontiac Sunfire, 2003 Pontiac Grand Am, 2003 Oldsmobile Alero, and 2003 Chevrolet Cavalier. However, it is still accessible from the selected car via links, so may be relevant.
The brake switch indicates brake pedal status to the Powertrain Control Module (PCM). The normally-closed brake switch supplies ignition voltage to the PCM. Applying the brake pedal opens the switch, interrupting voltage to the PCM. Releasing the brake pedal resumes voltage to the PCM. When the PCM senses zero volts at the brake switch input, the PCM de-energizes the Torque Converter Clutch (TCC) solenoid valve. Models equipped with cruise control systems may monitor the brake switch circuit to determine when to engage and disengage cruise control.