Circuit Description
WARNING: This page is about a different car, the 2006 Suzuki Reno and 2006 Suzuki Forenza. However, it is still accessible from the selected car via links, so may be relevant.
Brake lamp switch is a normally open switch that closes when the brake pedal is depressed. When the brake pedal is depressed, the bake lamp switch supplies signal voltage to the brake lamp switch signal circuit. Brake pedal switch is a normally closed switch that opens when the brake pedal is depressed.
The Engine Control Module (ECM) monitors the brake lamp switch signal circuit and the brake pedal switch signal circuit. The ECM monitors the status of the brake lamp switch signal circuit and the brake pedal switch signal circuit to see if they match when the brake pedal is pressed or released.