Automatic Lighting Control (ALC)

The Body Control Module (BCM) monitors circuit 79 to determine if the headlamps (park lamp) switch is active or inactive. The Automatic Light Control (ALC) system will be inactive if the headlamp, parklamp switch is active. The headlamp relay is commanded on by the BCM through circuit 352. The BCM also monitors 352 for feedback when the headlamp relay is commanded. The system uses light sensor circuit 1137 to switch the ALC on after dark.