P0703

DTC P0703: Stoplight Switch Malfunction














DESCRIPTIONS OF MONITOR METHODS

- Drive the vehicle at 30 km/h (18.6 mph) or more for 10 seconds, and then turn the ignition switch to the "LOCK" (OFF) position. In this sequential operation, no variation has been found in the stoplight switch input signal in two consecutive times.

MONITOR EXECUTION

- Drive with the vehicle speed 30 km/h (18.6 mph) or more for 10 seconds or more.

MONITOR EXECUTION CONDITIONS (OTHER MONITOR AND SENSOR)

Other Monitor (There is no temporary DTC stored in memory for the item monitored below)

- Not applicable
Sensor (The sensor below is determined to be normal)

- Not applicable

LOGIC FLOW CHARTS (Monitor Sequence)





DTC SET CONDITIONS

Check Conditions

- Vehicle speed over 30 km/h (18.6 mph): 10 seconds or more.
Judgment Criteria

- The change of brake switch signal during driving cycle: no occurrence. (10 seconds)

- Stoplight switch signal fail: 2 count or more. (10 seconds)

OBD-II DRIVE CYCLE PATTERN

Drive with the vehicle speed 30 km/h (18.6 mph) or more for 10 seconds or more, and then stop the vehicle. Again, drive with the vehicle speed 30 km/h (18.6 mph) or more for 10 seconds or more, and then stop the vehicle.

PROBABLE CAUSES

- Malfunction of the CAN bus

- Malfunction of the stoplight switch

- Damaged wiring harness and connectors

- Malfunction of TCM

- Malfunction of ETACS-ECU

DIAGNOSTIC PROCEDURE

STEP 1. Using scan tool MB991958, diagnose the CAN bus line.

Use scan tool to perform the CAN bus diagnosis.

Q. Is the check result normal?

YES Go to Step 2.
NO Repair the CAN bus lines CAN Bus Diagnostics Chart).
STEP 2. M.U.T.-III data list

Item 60: Brake switch

OK: The service data changes in response to the brake operation.


Q. Is the check result normal?

YES Intermittent malfunction
NO Go to Step 3.
STEP 3. Check the following connector:

- C-304 ETACS-ECU connector

- C-312 ETACS-ECU connector

- C-124 Stoplight switch connector

Check the contact status of the terminals.

Q. Is the check result normal?

YES Go to Step 4.
NO Repair the defective connector.
STEP 4. Stoplight Switch Check

Testing and Inspection.

Q. Is the check result normal?

YES Go to Step 5.
NO Replace the stoplight switch.
STEP 5. Check for open circuit in the wiring harness between the stoplight switch connector and the ETACS-ECU connector.

Between C-124 Stoplight switch connector (terminal No.1) and C-304 ETACS-ECU harness-side connector (terminal No.1)

Q. Is the check result normal?

YES Go to Step 6.
NO Repair the wiring harness.
STEP 6. Check for open circuit or short to ground in wiring harness between the stoplight switch connector and the ETACS-ECU

Between C-124 Stoplight switch connector (terminal No. 2) and C-312 ETACS-ECU harness-side connector (terminal No. 16)

Q. Is the check result normal?

YES Go to Step 7.
NO Repair the wiring harness.
STEP 7. Symptom recheck after erasing diagnostic trouble code

Q. Is the check result normal?

YES Intermittent malfunction
NO Replace the ETACS-ECU, and then go to Step 8.
STEP 8. Symptom recheck after erasing diagnostic trouble code

Q. Is the check result normal?

YES Intermittent malfunction
NO Replace TCM.