Ambient Light Sensor
The scan tool displays the output voltage of the ambient light sensor based on the intensity of light detected. As the light intensity increases, the sensor displayed voltage increases. In the LIGHT state, a high voltage (2.2-4.7 volts) is present and the DRL will be ON. In the DARK state, a low voltage (0.2-1.3 volts) is present and the headlamps will be ON.