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.
-
This step is performed in order to confirm that DTC P0703 is current within the TCM.
-
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 | |
Is DTC P0703 current in the transmission control module (TCM)? | Go to Step 3 | Go to Diagnostic Aids | |
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 |
Is there any DTC set again? | Go to Step 2 | System OK |
