P0703

DTC P0703

CIRCUIT 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 class 2 serial data message to the powertrain control module (PCM)/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 PCM/ECM receives an invalid brake pedal status class 2 serial data message from the BCM.
- This diagnostic runs continuously.

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

CONDITIONS FOR CLEARING THE DTC
- A last test failed, or the current DTC, clears when the diagnostic runs and does not fail.
- A history DTC clears after 40 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 BCM has been replaced, the brake pedal position (BPP) sensor must be calibrated. Refer to Brake Pedal Position Sensor Calibration.
- This DTC may be stored as a history DTC without affecting the operation of the BCM. If stored only as a history DTC and not retrieved as a current DTC, do not replace the BCM.
- If this DTC is retrieved as both a current and a history DTC, replace the BCM.
- For an intermittent condition, refer to Testing for Intermittent Conditions and Poor Connections. Component Tests and General Diagnostics

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 PCM/ECM.
3. This step is performed in order to correct a BPP sensor that must be calibrated, possibly due to a BCM replacement or for a BPP sensor that is out of adjustment.