DTC B2647: Ambient Light Sensor Signal Short To Ground/Open: Description

DTC B2647 indicates that ambient light sensor is shorted to ground or open. DTC B2647 will set when ALC option is enabled, Ignition 1 is active, and ambient light sensor analog input is 5 counts or less for 5 seconds.

When DTC B2647 is set, headlights will stay on at all times at full intensity. DTC B2647 can be cleared using scan tool, or history DTC will disappear after 100 ignition cycles if fault conditions do not reoccur.