B2645

DTC B2645

Circuit Description

The body control module (BCM) uses the ambient light sensor signal in order to control the Daytime Running Lamps (DRL) System. The ambient light sensor is connected to the BCM through the signal circuit and the reference circuit of the ambient light sensor.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B2645 Ambient Light Sensor Circuit High

Conditions for Running the DTC

* Voltage supplied to the module is in the normal operating range approximately 10-16 volts.
* The DRL feature must be enabled.

Conditions for Setting the DTC

* The BCM detects a short to battery positive voltage in the ambient light sensor reference voltage circuit.
* The condition is present for longer than 3 ms.

Action Taken When the DTC Sets

* The BCM stores DTC B2645 in memory.
* The SERVICE VEHICLE SOON telltale illuminates.

Conditions for Clearing the MIL/DTC

* A current DTC B2645 clears when the BCM no longer detects an short to battery positive voltage in the ambient light sensor reference voltage circuit.
* A history DTC B2645 clears after 100 consecutive ignition cycles.

Diagnostic Aids

* If the DTC B2645 is a history DTC, the fault may be intermittent. Refer to Testing for Intermittent Conditions and Poor Connections. Component Tests and General Diagnostics
* An intermittent short to battery positive voltage in the following locations may cause an intermittent malfunction to occur:

- The ambient light sensor reference voltage circuit
- The ambient light sensor
- The BCM

Test Description

Step 1 - Step 7:

The number below refers to the step number on the diagnostic table.
2. This step tests the ambient light sensor reference voltage circuit for a short to battery positive voltage.