P0703

DTC P0703

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* ReviewStrategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) 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 is 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)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

* Cruise Control Description and Operation (Description and Operation)
* Exterior Lighting Systems Description and Operation (Exterior Lighting Systems Description and Operation)

Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

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

Circuit/System Verification

1. Repair any brake system related DTCs before performing this diagnostic.
2. Verify that DTC P0572 or P0573 is not set as current.

• If either DTC is set, Refer to DTC P0572 or P0573 (P0572).

3. Verify that DTC P0703 is not set.

• If DTC P0703 is set as current, replace the BCM. Clear the DTC and road test the vehicle. If DTC P0703 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