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.

### Circuit/System Description

The instrument panel cluster (IPC) illuminates the high beam indicator when the BCM detects that the high beams are requested. The IPC receives a class 2 message from the BCM requesting illumination.

### Reference Information

#### Schematic Reference

Instrument Cluster 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

Ignition ON, turn the headlamp dimmer switch to the high beam position and observe the headlamps and the IPC high beam indicator. The high beam headlamps and the high beam indicator should illuminate.

### Circuit/System Testing

Ignition ON, with a scan tool perform the Display Test for the instrument panel cluster (IPC) and observe the high beam indicator.

⇒ | If the high beam indicator does not illuminate during the test or remains illuminated at all times, replace the IPC.

⇒ | If the high beam indicator illuminates during the test, replace the BCM.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for BCM or IPC replacement, setup, and programming.