C0297

DTC C0297

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.

DTC Descriptor
DTC C0297 02
- Brake Applied Output Circuit Short to Ground

Diagnostic Fault Information





Circuit/System Description

The stop lamp switch signal circuit is a B+ input from the body control module (BCM) to the engine control module (ECM). The ECM monitors the stop lamp switch circuit to detect when the brake pedal has been applied. The BCM monitors the brake pedal position sensor to determine when the brake pedal is applied. When the brake pedal is applied, the BCM supplies 12V on the stop lamp switch signal circuit and also sends a serial data message to the ECM indicating that the brake pedal has been applied.

Conditions for Setting the DTC

The BCM detects a short to ground on the cruise/ETC/TCC brake signal circuit.

Action Taken When the DTC Sets

The cruise control system is disabled

Conditions for Clearing the DTC

* The DTC will be current for as long as the fault is present.
* When the fault is no longer present, the DTC will be a history DTC.
* A history DTC will clear after 50 ignition cycles.

Reference Information
Schematic Reference

Cruise Control Schematics (Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector End Views By Name)
Description and Operation

Exterior Lighting Systems Description and Operation (Exterior Lighting Systems)
Electrical Information Reference

* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)

Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information

Circuit/System Testing

1. Ignition OFF, disconnect the X1 (LF1) or X2 (LAU) harness connector at the K20 ECM.
2. Connect a test lamp between the signal circuit terminal listed below and ground:

* Terminal 57 (LF1)
* Terminal 52 (LAU)

3. Ignition ON, observe the function of the test lamp while pressing and releasing the brake pedal. The test lamp should turn ON when the brake pedal is pressed and turn OFF when the brake pedal is released.

• If the test lamp is always ON, test the signal circuit for a short to voltage.
• If the test lamp is always OFF, test the signal circuit for a short to ground or an open/high resistance.

4. If all circuits test normal, replace the K9 BCM.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

Control Module References (Programming and Relearning) for BCM replacement, setup and programming