Circuit/System Description

The ambient light sensor is used to monitor outside lighting conditions. The ambient light sensor provides a voltage signal that will vary between 1.4-4.5 V depending on outside lighting conditions. When the headlamp switch is in the AUTO position, the body control module (BCM) monitors the ambient light sensor signal circuit to determine if outside lighting conditions are correct for either daytime running lights or automatic lamp control. In daylight conditions, the BCM will command the daytime running lights ON. During low light conditions, the BCM will command the low beam headlamps ON.