B2645
DTC B2645
Circuit Description
The body control module (BCM) monitors the ambient light sensor signal circuit in order to determine if the daytime running lights (DRL) or the automatic lamp control (ALC) should be turned ON in the AUTO mode. When the BCM senses the ambient light sensor voltage is between 1.75-4.9 volts, either the DRL will be commanded ON or the ALC will be commanded ON.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC B2645 Ambient Light Sensor Circuit
Conditions for Running the DTC
The system voltage must be between 9-16 volts.
Conditions for Setting the DTC
B2645.01
Will set if there is a short to voltage in the ambient light sensor signal circuit.
B2645.02
Will set if there is an open or short to ground in the ambient light sensor signal circuit.
Action Taken When the DTC Sets
The ALC will remain ON in any ambient light state.
Conditions for Clearing the MIL/DTC
* This DTC will clear immediately after the condition for setting the fault is corrected.
* A history DTC will clear after 100 consecutive ignition cycles without a fault present.
* Use a scan tool in order to clear history and current DTCs.
Diagnostic Aids
* The following may cause an intermittent:
- Bent terminal
- Backed out terminal
- Damaged terminal
- Poor terminal tension
- Chafed wire
- Broken wire inside the insulation
* When diagnosing for an intermittent short or an open, manipulate the wire harness while watching the test equipment for changes.
Test
