Circuit/System Description
WARNING: This page is about a different car, the 2007 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
The stoplamp switch is used to sense the action of the driver application of the brake pedal. The stoplamp switch will apply battery voltage to the park/stoplamp signal voltage supply circuit to illuminate the stop lamps and the center high mounted stop lamp (CHMSL). The stoplamp switch also sends a signal to the powertrain control module (PCM) as well to indicate the application of the brake pedal.