Stop Lamp Switch
The task of the stop lamp switch is to provide the engine control module (ECM) with information about the position of the brake pedal.
When the brake pedal is pressed down, a signal is sent to the Engine control module (ECM) which turns off the cruise control (if it is activated). The brake pedal switch function (connected to the brake control module (BCM)) also handles the function for switching off the cruise control.
The stop lamp switch is supplied with power from the start control module (SCU) (terminal 30). When the brake pedal is depressed the switch closes and a high signal (12 V) is transmitted to the engine control module (ECM).
The engine control module (ECM) can diagnose the stop lamp switch. The status (position) of the switch can be read using the diagnostic tool.
The brake light switch is on the pedal box by the brake pedal.