For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions 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

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Exterior Lighting Systems Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

Control Module References 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 after completing the diagnostic procedure.

Control Module References for headlamp control module replacement, setup, and programming