B2647

DTC B2647

CIRCUIT DESCRIPTION
The body control module (BCM) uses the DRL ambient light sensor to control the automatic headlamp system. The DRL ambient light sensor is connected directly to the BCM through the DRL ambient light sensor signal circuit and the DRL ambient light sensor low reference circuit.

CONDITIONS FOR RUNNING THE DTC
The DRL feature or the automatic headlamp control feature must be enabled.

CONDITIONS FOR SETTING THE DTC
- The BCM detects a short to ground in the DRL ambient light sensor signal circuit.
- The ambient light sensor is internally shorted.
- The condition above must be present for more than 0.3 seconds.

ACTION TAKEN WHEN THE DTC SETS
- The BCM stores DTC B2647 in memory.
- The SERVICE VEHICLE SOON telltale illuminates
- The headlamps, park lamps, tail lamps and marker lamps will illuminate to night intensity.

CONDITIONS FOR CLEARING THE DTC
- The BCM no longer detects a short to ground in the DRL ambient light sensor signal circuit.
- A history DTC B2647 will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present.

DIAGNOSTIC AIDS
- If the DTC B2647 is a history DTC, the fault may be intermittent.
- The following conditions may cause an intermittent malfunction to occur:
- An intermittent short to ground in the DRL ambient light sensor signal circuit.
- The DRL ambient light sensor is intermittently shorted to ground internally.
- The BCM is intermittently shorted to ground internally.

TEST

Steps 1 - 2:

Steps 3 - 6:

Steps 7 - 12: