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 B0655 5A: Brake Lamp Switch Circuit Not Plausible

### Circuit/System Description

The brake pedal position sensor is used to sense the action of the driver application of the brake pedal. The brake pedal position sensor provides an analog voltage signal to the body control module (BCM). The BCM will apply battery voltage to the right, left and center stop lamp control circuits and the trailer lighting converter. The trailer lighting converter receive also a serial data message from the BCM.

### Conditions for Running the DTC

• | The ignition is in OFF, ACCESSORY or RUN position.

• | The system voltage is between 9-16 V

### Conditions for Setting the DTC

The trailer lighting converter detects a difference between the hardwired signal and the serial data message.

### Action Taken When the DTC Sets

The trailer lighting converter stores the DTC in the failure record.

### Conditions for Clearing the DTC

The condition for setting the DTC is no longer present.

### Reference Information

#### Schematic Reference

Exterior Lights Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Exterior Lights Schematics

#### 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 B3884 is not present.

⇒ | If DTC is present, refer to DTC B3884

⇒ | If DTC is not present, replace the K68 Trailer Lighting Converter

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for trailer lighting converter replacement, setup and programming