Brake Light Switch
The purpose of the brake light switch is to provide the engine control module (ECM) with information indicating whether the brake pedal is depressed.
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 position sensor also handles the function for switching off cruise control.
The brake light switch is supplied with power from the ignition switch (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 stop lamp switch can be diagnosed by the engine control module (ECM) and its status (depressed or not) can be read off.
The brake light switch is on the pedal box by the brake pedal.