B2555
DTC B2555
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions)provides an overview of each diagnostic category.
DTC Descriptor
DTC B2555 05
- Passenger Compartment Lamp Control Circuit Short to Battery or Open
Diagnostic Fault Information
Circuit/System Description
The body control module (BCM) applies battery voltage to the courtesy lamps through the courtesy lamps control circuit. When any door is opened, the door ajar switch contacts close and the BCM receives a door-open input. If the BCM receives a door lock or unlock input or a rear hatch open input, the BCM will activate the courtesy lamps control circuit, providing battery voltage to all of the dome lamps and reading lamps. The dome lamps are provided with battery voltage via the courtesy lamps control circuit and ground through the courtesy lamps low control circuit. In the event that any of these lamps were to remain illuminated for more than 20 minutes with the ignition switch in the OFF position, the BCM will deactivate the courtesy lamp high control circuit to prevent a total battery discharge condition.
Conditions for Running the DTC
Battery voltage must be between 9-16 V.
Conditions for Setting the DTC
The BCM detects a short to voltage or an open in the courtesy lamp low control circuit.
Action Taken When the DTC Sets
The dome lamps will not illuminate when a door is opened.
Conditions for Clearing the DTC
* The condition responsible for setting the DTC no longer exists.
* A history DTC will clear once 100 consecutive malfunction-free ignition cycles have occurred.
Reference Information
Schematic Reference
Interior Lights Schematics (Interior Lights Schematics)
Connector End View Reference
Component Connector End Views (Connector End Views By Name)
Description and Operation
Interior Lighting Systems Description and Operation (Interior Lighting Systems)
Electrical Information Reference
* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)
Scan Tool Reference
Control Module References (Programming and Relearning)for scan tool information
Circuit/System Testing
Note: Each courtesy lighting component may need to be disconnected to isolate a short to voltage or short to ground. Use the schematic to identify the following:
* Courtesy lighting components the vehicle is equipped with.
* Component locations on the interior lighting schematic
* Each component's control and ground circuit terminals
1. Ignition OFF, disconnect the harness connector at any component with inoperative courtesy lighting.
2. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal B and ground.
• If the test lamp does not illuminate, test the control circuit for a short to ground or an open/high resistance.
3. Connect a test lamp between the B+ circuit terminal B and the control circuit terminal A.
4. Command the Interior Lamps ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
• If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the BCM.
• If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
5. If all circuits test normal, test or replace the courtesy light.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Refer to the appropriate replacement procedure for the component causing the condition
* Control Module References (Programming and Relearning)for BCM replacement, setup, and programming