B257D

DTC B257D

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.

DTC Descriptor
DTC B257D 00
- Right Headlamp Assembly

Circuit/System Description

On vehicles equipped with adaptive forward lighting, the headlamps can turn left and right to improve visibility during turns.

Conditions for Running the DTCs

* Ignition ON.
* Gear selector in DRIVE.
* Headlamp switch in AUTO position.
* The ambient light sensor indicating Night.
* Vehicle speed greater than 2 km/h (1.3 mph).
* The steering wheel is turned greater than 10 degrees to the right or left.

Condition for Setting the DTC

A malfunction in the adaptive forward lighting system.

Action Taken When the DTC Sets

The adaptive forward lighting system is inoperative for the remainder of the ignition cycle.

Conditions for Clearing the DTC

The conditions for setting the DTC are no longer present.

Reference Information
Schematic Reference

Headlights/Daytime Running Lights (DRL) Schematics (Headlights/Daytime Running Lights (DRL) Schematics)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Exterior Lighting Systems Description and Operation (Exterior Lighting Systems Description and Operation)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information

Circuit/System Verification

Verify that DTC B257D is not set.

If the DTC is set, replace the right headlamp control module.

Repair Instructions

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

Control Module References (Programming and Relearning) for headlamp control module replacement, setup, and programming