Stop Light Switch Circuit: Description

When the brake pedal is depressed, the stop light switch turns on and transmits an STP signal to the ECM. Upon receipt of the STP signal, the ECM determines that the brakes have been applied. The signal voltage level is the same as that of the voltage which is applied to the stop lights. In addition, the STP signal is used to control the fuel cut-off engine speed. Therefore, the fuel cut-off engine speed is slightly reduced when the vehicle is braking.