The sensor located directly behind the brake pedal activates the stop lights as the pedal is pressed. If it fails, the driver behind you will have no way of knowing that you are braking and, consequently, may hit your car.
A faulty sensor may completely disable the stop lights
You should check the sensor and the stop lights as often as possible
Range of services
Removing the panels under the steering column
Disconnecting the sensor from the electrical system
Fitting a new sensor in
Connecting the new sensor to the electrical system