For 1990-2009 cars

### Circuit Description

The Electronic Brake Control Module (EBCM) monitors the BPP sensor. When the brake pedal is applied, the EBCM detects a predetermined voltage signal. The EBCM sends a class 2 serial data message to the TCM and the ECM, indicating the status of the stop lamps.

### DTC Descriptor

The diagnostic procedure supports the following DTCs:

DTC P0703 Brake Switch Circuit 2

### Conditions for Running the DTC

Turn ON the ignition.

### Conditions for Setting the DTC

• | The TCM and the ECM receive an invalid brake pedal status class 2 serial data message from the EBCM.

• | The diagnosis runs continuously.

### Actions Taken When the DTC Sets

• | 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) does not illuminate.

• | The TCM or ECM records the operating status at the time the diagnostic fails. The TCM or ECM stores this information in the Failure Records.

### Conditions for Clearing the DTC

• | A last 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.

• | Clear away all DTCs with scan tool.

### Diagnostic Aids

• | If an EBCM has been replaced, the BPP sensor must be calibrated. Refer to Brake Pedal Position Sensor Calibration .

• | This DTC will be stored as a history DTC without affecting the operation of the module. If stored only as a history DTC and not retrieved as a current DTC, do not replace the module.

• | For an intermittent condition, refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

### Test Description

The following numbers are corresponding to the steps in the diagnostic table.

1. This step is performed in order to confirm that DTC P0703 is current within the TCM.

2. This step is performed in order to correct a BPP sensor that must be calibrated, possibly due to an EBCM replacement or for a BPP sensor that is out of adjustment.

Step | Action | Yes | No
--- | --- | --- | ---
Schematic Reference: Cruise Control Schematics Connector End View Reference: Cruise Control Connector End Views or Antilock Brake System Connector End Views Important: Repair all DTCs related to the stop lamps and to the brake system before performing this table.
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle
2 | Is DTC P0703 current in the transmission control module (TCM)? | Go to Step 3 | Go to Diagnostic Aids
3 |

1. Perform the BPP sensor calibration procedure. Refer to Brake Pedal Position Sensor Calibration .
2. Clear away all DTCs with scan tool.
3. Operate the vehicle according to the conditions for running the DTC.

Is there any DTC set again?

Go to Step 4

System OK

4 | Inspect for poor connections at the harness connector of the electronic brake control module (EBCM). Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs . Did you find and correct the condition? | Go to Step 6 | Go to Step 5
5 | Replace the EBCM. Refer to Control Module References . Is the replacement completed? | Go to Step 6 | --
6 |

1. Clear away all DTCs with scan tool.
2. Operate the vehicle in the Conditions for Running the DTC.

Is there any DTC set again?

Go to Step 2

System OK