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 B3445 00: Stop Lamp Circuit

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
CHMSL Control | B3445 00 | 1 | 2 | --
1. Stop Lamps Inoperative 2. Stop Lamps Always On

### Circuit/System Description

Battery voltage for the center high mounted stop lamp (CHMSL) is applied from the CHMSL/DMR/LAMP fuse in the I/P electrical center to the body control module (BCM). When the brake pedal is applied, a signal is applied to the BCM. The BCM then applies a voltage to the CHMSL control circuit to the CHMSL.

### Conditions for Running the DTC

The ignition is ON. The stop lamps must be commanded ON.

### Conditions for Setting the DTC

The BCM receives a ground signal on the CHMSL voltage supply circuit when the stop lamps are being commanded ON.

### Action Taken When the DTC Sets

The CHMSL does not illuminate.

### Conditions for Clearing the DTC

The BCM clears this code from current when the fault is removed from the system.

### Reference Information

#### Schematic Reference

Exterior Lights Schematics

#### Connector End View Reference

Component Connector End Views

#### 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, press the brake pedal. The CHMSL should illuminate.

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the CHMSL.
2. Verify that a test lamp illuminates between the ground circuit terminal 2 and B+.

⇒ | If the test lamp does not illuminate, test the ground circuit for an open/high resistance.

3. Connect a test lamp between the control circuit terminal 1 and ground.
4. Ignition ON, press and release the brake pedal. The test lamp should turn ON and OFF when pressing and releasing the brake pedal.

⇒ | If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the BCM.

⇒ | If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.

5. If all circuits test normal, test or replace the CHMSL.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | High Mount Stop Lamp Replacement

• | Control Module References for BCM replacement, setup, and programming