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 End Views By Name)
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 (Programming and Relearning) 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 (Programming and Relearning) for BCM, ECM or PCM replacement, setup, and programming