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 02
- Passenger Compartment Lamp Control Circuit Short to Ground

Diagnostic Fault Information





Circuit/System Description

The body control module (BCM) supplies a reference voltage to the backlight dimmer switch, which is part of the headlamp switch. When the backlight dimmer switch is placed in a desired brightness position, reference voltage is applied through the dimmer switch to the BCM. The BCM interprets this voltage signal, then applies a variable voltage through the LED backlight lamp control circuit illuminating the components listed below:

* Accent lamp - driver door
* Accent lamp - passenger door

Conditions for Running the DTC

* The ignition is ON.
* The headlamps or park lamps are ON.

Conditions for Setting the DTC

The BCM detects a short to ground on the LED backlight lamp control circuit.

Action Taken When the DTC Sets

The BCM will not dim or illuminate any LED backlighting supplied by the backlight lamp control circuits.

Conditions for Clearing the DTC

* The condition responsible for setting the DTC no longer exists.
* A history DTC will clear once 100 consecutive malfunction ignition cycles have occurred.

Reference Information
Schematic Reference

Interior Lights Schematics (Interior Lights Schematics)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Interior Lighting Systems Description and Operation (Interior Lighting Systems Description and Operation)
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 Verification

Command the Accent Lighting test ON and OFF with a scan tool. The appropriate accent lamp should be ON and OFF.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the appropriate accent lamp.
2. Test for less than 5 ohm between the black wire of the appropriate and ground.

• If greater than the specified range, test the ground circuit for an open/high resistance.

3. Connect a test lamp between the appropriate accent lamp control circuit terminal B and ground or between the appropriate accent lamp control circuit terminal C and ground.
4. Command the Accent Lighting test 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 voltage. If the circuit tests normal, replace the K9 Body Control Module.
• If the test lamp is always OFF, test the control circuit for a short to round or open/high resistance. If the circuit tests normal, replace the K9 Body Control Module.

5. If the all circuits test normal, replace appropriate accent lamp.

Repair Instructions

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

* Rear Side Door Inside Handle Illumination Lamp Replacement (Rear Side Door Inside Handle Illumination Lamp Replacement)
* Front Side Door Inside Handle Illumination Lamp Replacement (Front Side Door Inside Handle Illumination Lamp Replacement)
* Control Module References (Programming and Relearning) for BCM replacement, setup, and programming