P0703

DTC P0703

CIRCUIT DESCRIPTION
The instrument panel module (IPM) monitors the brake pedal position (BPP) sensor. When the brake pedal is applied, the IPM detects a predetermined voltage signal. The IPM sends a GMLAN serial data message to the transmission control module (TCM) and to the engine control module (ECM) indicating the status of the stop lamps.

DTC DESCRIPTOR
This diagnostic procedure supports the following DTC:
DTC P0703 Brake Switch Circuit 2

CONDITIONS FOR RUNNING THE DTC
The engine is ON.

CONDITIONS FOR SETTING THE DTC
- The TCM or the ECM receives an invalid brake status GMLAN serial data message from the IPM.
- This diagnostic runs continuously.

ACTION TAKEN WHEN THE DTC SETS
- Autograde braking is inhibited.
- The Cruise Control System is disabled.
- The TCM or the ECM stores the DTC information into memory when the diagnostic runs and fails.
- The malfunction indicator lamp (MIL) will not illuminate.
- The TCM or the ECM records the operating conditions at the time the diagnostic fails. The TCM or the ECM stores this information in the Failure Records.

CONDITIONS FOR CLEARING THE DTC
- The DTC becomes history when the fault is no longer present.
- A history DTC clears after 100 consecutive warm-up cycles, if failures are not reported by this or any other emission related diagnostic.
- Use the scan tool in order to clear the DTC.

DIAGNOSTIC AIDS
- Repair any brake system related DTCs before performing this diagnostic table.
- If an IPM has been replaced, the BPP sensor must be calibrated. Refer to Brake Pedal Position Sensor Calibration in Lighting System.
- This DTC may be stored as a history DTC without affecting the operation of the IPM. If stored only as a history DTC and not retrieved as a current DTC, do not replace the IPM.
- If this DTC is retrieved as both a current and a history DTC, replace the IPM.
- For an intermittent condition, refer to Testing for Intermittent Conditions and Poor Connections in Diagnostic Aids.

TEST DESCRIPTION

Step 1 - Step 6:

The numbers below refer to the step numbers located in the diagnostic table.
2. This step is performed in order to confirm that DTC P0703 is current within the TCM or the ECM.
3. This step is performed in order to correct a BPP sensor that must be calibrated, possibly due to a IPM replacement or for a BPP sensor that is out of adjustment.