P0703

DTC P0703

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 P0703
- Brake Switch Circuit 2

Circuit/System Description

The body control module (BCM) monitors the brake pedal position sensor. When the brake pedal is applied, the BCM detects a predetermined voltage signal. The BCM sends a serial data message to the engine control module (ECM)/powertrain control module (PCM) indicating the status of the stop lamps.

Conditions for Running the DTC

The engine is ON.

Conditions for Setting the DTC

* The ECM/PCM receives an invalid brake pedal status serial data message from the BCM.
* This diagnostic runs continuously.

Actions Taken When the DTC Sets

* The cruise control system becomes disabled.
* The malfunction indicator lamp (MIL) will not illuminate.

Conditions for Clearing the DTC

* The condition responsible for setting the DTC no longer exists.
* A history DTC will clear after 40 malfunction-free ignition cycles have occurred.

Reference Information
Schematic Reference

* Cruise Control Schematics Electrical Diagrams
* Exterior Lights Schematics Exterior Lights Schematics

Connector End View Reference

Component Connector End Views Connector Views
Description and Operation

Cruise Control Description and Operation Description and Operation
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 Control Module References for scan tool information

Circuit/System Verification

1. Verify that DTC P0572 or P0573 is not set.

• If DTC is set, refer to Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle.

2. Verify that DTC P0703 is not set.

• If DTC is set, replace the BCM. Clear the DTC and road test the vehicle. If DTC resets, replace the ECM/PCM.

Repair Instructions

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

Control Module References Control Module References for BCM, ECM or PCM replacement, setup, and programming