Circuit Description

The ambient light sensor is an input to the Body Control Module (BCM). BCM uses the light sensor input to determine the level of light to turn headlights on or off automatically. BCM monitors the 5-volt reference circuit to light sensor. If BCM does not see 5 volts on this circuit, DTC will set. BCM also monitors ignition switch position based on ignition signal inputs. BCM performs a self-test on power up.

Conditions for setting DTC:

• Ambient light sensor circuit(s) shorted to ground.
• System voltage 9-16 volts.
• Conditions met for .5 second.