FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
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B255F




DTC B255F

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 Descriptors

DTC B255F 02
- Interior Door Handle Backlight Circuit Short to Ground

DTC B255F 04
- Interior Door Handle Backlight Circuit Open

Diagnostic Fault Information






Circuit/System Description

The instrument panel (I/P) dimmer switch is used to increase and decrease the brightness of the interior backlighting components. The I/P dimmer switch provides a voltage signal to the body control module (BCM) that will increase as the brightness of the lights are increased and decrease as the brightness of the lights are decreased. The BCM provides a low reference signal and a B+ voltage reference to the I/P dimmer switch. When the I/P dimmer switch is placed in the desired position, the dimmed voltage setting is applied from the I/P dimmer switch through the I/P dimmer switch signal circuit to the BCM. The BCM interprets the signal and applies a pulse width modulated (PWM) voltage to the accent lamp control circuit illuminating all of the accent lighting. The accent lighting will remain illuminated until all doors are closed and the ignition is OFF. The accent lighting remains illuminated with the ignition ON.

Conditions for Running the DTC

Battery voltage must be between 9-16 V.

Conditions for Setting the DTC

DTC B255F 02

The BCM detects a short to ground in the accent lamp control circuit terminal 22 X7

DTC B255F 04

The BCM detects an open/high resistance in the accent lamp control circuit terminal 22 X7

Actions Taken When the DTC Sets

The BCM will disable the accent lamp control circuit.

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 Dimming Schematics Interior Lights Dimming Schematics

Connector End View Reference

Component Connector End Views Outside Rearview Mirror - Driver

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 Control Module References for scan tool information

Circuit/System Testing

Note: Each component with backlighting may need to be disconnected to isolate a short to voltage or short to ground. Use the schematics to identify the following:

* Backlighting components the vehicle is equipped with

* Each component's control and ground circuit terminals

* Component locations on the backlighting control circuit

1. Ignition OFF, exterior lamps OFF, disconnect the harness connectors at the component with the inoperative LED backlighting.

2. Connect a test lamp between the appropriate control circuit terminal listed below and ground.

* E1D accent lamp - driver door - terminal 1

* E1P accent lamp - passenger door - terminal 1

* E1Q accent lamp - console cupholder left - terminal 1

* E1S accent lamp - console cupholder right - terminal 1

3. Verify the test lamp turns ON and OFF when commanding the Accent Lighting ON and OFF with a scan tool.

If the test lamp is always OFF

1. Ignition OFF, disconnect the X7 harness connector at the K9 body control module.

2. Test for infinite resistance between the control circuit and ground.

If less than infinite resistance, repair the short to ground on the circuit.

If infinite resistance

3. Test for less than 2 ohms in the control circuit end to end.

If 2 ohms or greater, repair the open/high resistance in the circuit.

If less than 2 ohms, replace the K9 body control module.

If the test lamp is always ON

1. Ignition OFF, disconnect the X7 harness connector at the K9 body control module, ignition ON.

2. Test for less than 1 V between the control circuit terminal and ground.

If 1 V or greater, repair the short to voltage on the circuit.

If less than 1 V, replace the K9 body control module.

If the test lamp turns ON and OFF

4. Test or replace the appropriate E1 accent lamp.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the repair.

* Front Side Door Courtesy Lamp Replacement Front Side Door Courtesy Lamp Replacement

* Control Module References Control Module References for BCM replacement, programming, and setup