Daytime Running Lamp (DRL) Ambient Light Sensor

The headlamp automatic control ambient light sensor is located to the right of the heat and air conditioning duct, in the center of the I/P.

As the intensity of the light reaching the sensor increases, the electrical resistance of the sensor decreases. When the DRL control module senses a low resistance in the sensor, the module allows voltage to be applied to the DRL diode and then to the headlamps. Due to the voltage drop across the diode, the headlamps are on at a reduced intensity.

As the intensity of light reaching the sensor decreases, the electrical resistance of the sensor increases. When the DRL module senses a high resistance in the sensor, the module closes an internal relay and allows the headlamps to come to full intensity.