DTC P0719: Brake Switch Circuit - Low Input: Description
WARNING: This page is about a different car, the 2002 Pontiac Montana, 2002 Oldsmobile Silhouette, and 2002 Chevrolet Venture. However, it is still accessible from the selected car via links, so may be relevant.
The TCC brake switch indicates brake pedal status to the PCM. The TCC brake switch indicates that the brake pedal is either applied or released. The normally-closed switch supplies battery voltage to the PCM. Applying the brake pedal opens the TCC brake switch, interrupting voltage to the PCM. When the PCM receives 0 volts at the TCC brake switch input, the PCM turns OFF the Torque Converter Clutch Pulse Width Modulation (TCC PWM) solenoid valve. If the PCM detects an open brake switch, which indicates pedal applied during a number of accelerations, then DTC P0719 sets.