Code No. P0703: Malfunction of Stop Lamp Switch


DIAGNOSTIC FUNCTION


CVT-ECU detects malfunction using the stop lamp switch signal sent from the ETACS-ECU.

JUDGEMENT CRITERIA


Drive the vehicle at 30 km/h or more for 10 seconds, and then turn the ignition switch to the OFF position. In this sequential operation, no variation has been found in the stop lamp switch input signal in two consecutive times.

PROBABLE CAUSES



DIAGNOSTIC PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnostics
Use M.U.T.-III to perform the CAN bus diagnosis.

Q. Is the check result normal?
Go to Step 2.
Repair the CAN bus lines (Refer to GROUP 54C - Troubleshooting, Diagnosis Code Chart ).

STEP 2. M.U.T.-III data list
Item 50: Brake switch
OK: The service data changes in response to the brake operation.

Q. Is the check result normal?
Intermittent malfunction
Go to Step 3.

STEP 3. Stop Lamp Switch Check
Refer to GROUP 35A - Brake Pedal and Stop Lamp Switch Continuity Check (Refer to ).

Q. Is the check result normal?
Go to Step 4.
Replace the stop lamp switch.

STEP 4. Check for open circuit in STP line between the stop lamp switch connector and the ETACS-ECU connector

Q. Is the check result normal?
Go to Step 5.
Repair the connector(s) or wiring harness.

STEP 5. Check for open circuit or short to earth in BKLP line between the ETACS-ECU connector and the stop lamp switch connector

Q. Is the check result normal?
Go to Step 6.
Repair the connector(s) or wiring harness.

STEP 6. Symptom recheck after erasing diagnosis code

Q. Is the check result normal?
Intermittent malfunction
Replace the ETACS-ECU, and then go to Step 7.

STEP 7. Symptom recheck after erasing diagnosis code

Q. Is the check result normal?
Intermittent malfunction
Replace CVT-ECU.