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 high 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 lamp high control circuit, providing battery voltage to all of the dome lamps, reading lamps, rear compartment lamp, and vanity mirror lamps. The dome lamps switch consists of 3 positions, ON, DOOR, and OFF. When the dome lamp switch is placed in the DOOR position, the dome lamps will illuminate when a door is opened. The dome lamps are provided with battery voltage via the courtesy lamps high 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 volts.

Conditions for Setting the DTC

DTC B2555 05 will set when the BCM detects a short to voltage or an open in the courtesy lamp low control circuit.

Action Taken When the DTC Sets

When the DTC is present, 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

1. Ignition OFF, disconnect the harness connector at the appropriate dome/courtesy lamp assembly.
2. Connect a test lamp between B+ and the appropriate control circuit terminal listed below.

* Dome/reading lamps control terminal B - without C3Y
* Dome lamp control terminal B - with C3Y
* Courtesy/reading lamp control terminal C
* Courtesy lamp - left control terminal 2 - convertible
* Courtesy lamp - right control terminal 2 - convertible

3. 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 OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
• If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the BCM.

4. If all circuits test normal, replace the inoperative courtesy/reading lamp assembly.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.

* Dome Lamp Replacement (Sedan) Service and Repair
* Reading Lamp Bulb Replacement Service and Repair
* Quarter Courtesy Lamp Lens and Bulb Replacement Service and Repair
* Control Module References Programming and Relearning for BCM replacement, setup, and programming