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 C0297 00: Brake Applied Output Circuit

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Brake Signal | C0297 00 | -- | -- | --

### Circuit/System Description

The body control module (BCM) applies a ground through the brake pedal position sensor low reference circuit to the brake pedal position sensor (BPP). The BCM supplies a 5-volt reference through the brake sensor reference voltage circuit to the BPP. When the brake pedal is being applied, the BPP then sends a variable voltage through the brake sensor signal circuit to the BCM. The BCM then applies a signal to the brake signal circuit to the engine control module (ECM) and transmission control module (TCM).

### Conditions for Running the DTC

The ignition is ON.

### Conditions for Setting the DTC

The BCM detects a short to ground on the brake signal circuit.

### Action Taken When the DTC Sets

The ECM and TCM will not function correctly.

### Conditions for Clearing the DTC

The BCM clears these codes from current when the fault is removed from the system.

### Reference Information

#### Schematic Reference

Exterior Lights Schematics

#### Connector End View Reference

Lighting Systems Connector End Views

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

• | Scan Tool Output Controls

• | Scan Tool Data List

• | Scan Tool Data Definitions

### Circuit/System Verification

Ignition ON, press and release the brake pedal. The stop lamps should illuminate then go out.

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the ECM, and TCM.
2. Connect a DMM at the ECM, between the brake signal circuit and the positive terminal of the battery.
3. Ignition ON, test for less than 0.1 volt

⇒ | If greater than the specified range, test the brake signal circuit for a short to ground. If the circuit/connections test normal, replace the BCM.

4. Leave the DMM connected, connect the TCM harness connector.
5. Ignition ON, test for less than 0.1 volt

⇒ | If greater than the specified range, replace the TCM

6. If the voltage is correct and all circuits/connections test normal, replace the ECM.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Brake Pedal Position Sensor Replacement

• | Brake Pedal Position Sensor Calibration

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