Circuit Description

The body control module (BCM) monitors the courtesy lamp relay coil control circuit in order to determine if the daytime running lights (DRL) or the auto headlights (ALC) should be turned ON in the AUTO mode. When the BCM senses the ambient light sensor voltage is between 1.7 volts and 4.7 volts, the DRL will be commanded ON. When the BCM senses the ambient light sensor voltage is between 0.2 volts and 1.0 volts, the ALC will be commanded ON.