P0703

DTC P0703: Malfunction of Stoplight Switch














DIAGNOSTIC FUNCTION

TCM detects malfunction using the stoplight switch signal sent from the ETACS-ECU.

DESCRIPTIONS OF MONITOR METHODS

- Drive the vehicle at 30 km/h (19 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

- Continuous

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: 30 km/h (19 mph) or more.

- Voltage of battery: 9 volts or more.

- Voltage of battery: 16 volts or less.
Judgment Criteria

- The change of stoplight switch signal during driving cycle: no occurrence (10 seconds x 2 times).

OBD-II DRIVE CYCLE PATTERN

Drive the vehicle for 10 seconds or more at 30 km/h (19 mph) or higher (2 drive cycle)

PROBABLE CAUSES

- Malfunction of the CAN bus

- Malfunction of the stoplight switch

- Damaged wiring harness and connectors

- Malfunction of TCM

- Malfunction of ETACS-ECU

DIAGNOSIS

STEP 1. M.U.T.-III CAN bus diagnostics

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 50: 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-32 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-32 Stoplight switch connector (terminal No.2) 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. 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 7.
STEP 7. Symptom recheck after erasing diagnostic trouble code

Q. Is the check result normal?

YES Intermittent malfunction
NO Replace TCM.