B2647

DTC B2647

CIRCUIT DESCRIPTION




The body control module (BCM) uses the DRL ambient light sensor signal circuit to control the automatic headlamp control system. The ambient light sensor is connected directly to the BCM through the DRL ambient light sensor signal circuit and through 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 shorted internally.
- The condition above must be present for more than 5 seconds.

ACTION TAKEN WHEN THE DTC SETS
- The BCM stores DTC B2647 in memory.
- The headlamps, park lamps, tail lamps and marker lamps will illuminate to low light 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 condition is no longer present.
- The BCM receives the clear code command from the scan tool.

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

TEST

Steps 1 - 9:

Steps 10 - 11: