INSPECTION PROCEDURE 8: The rain sensitive AUTO wiper function works even though there is no rainfall <Vehicles with lighting control sensor>.


caution Whenever ECU is replaced, ensure that the input and output signal circuits are normal.

COMMENTS ON TROUBLE SYMPTOM
The lighting control sensor, the harness connector, or the ETACS-ECU may be defective.

PROBABLE CAUSES

  • Malfunction of the lighting control sensor
  • Malfunction of ETACS-ECU
  • Damaged wiring harness and connectors

DIAGNOSTIC PROCEDURE

STEP 1. Lighting control sensor installation surface check
Visually check the presence of scratches or air bubbles (diameter of 5 mm or more) on the windshield to which the lighting control sensor is installed.

Q. Is the check result normal?
Go to Step 2.
Replace the windshield (Refer to GROUP 42A - Windshield Removal and Installation ).

STEP 2. Windshield wiper operation check
Check that the windshield wipers work normally.

Q. Is the check result normal?
Go to Step 3.
Refer to trouble symptom chart .

STEP 3. M.U.T.-III diagnosis code
Check if an ETACS-related diagnosis code is set.

Q. Is the diagnosis code set?
Diagnose the ETACS-ECU (Refer to GROUP 54A - ETACS ).
Go to Step 4.

STEP 4. M.U.T.-III diagnosis code
Check if a lighting control sensor-related diagnosis code is set.

Q. Is the diagnosis code set?
Diagnose the lighting control sensor (Refer to GROUP 54A - Diagnosis Code Chart ).
Go to Step 5.

STEP 5. Measure the voltage at ETACS-ECU connector (LIN2 terminal).
(1)Disconnect the connector, and measure the voltage at the wiring harness side.
(2)Measure the voltage between ETACS-ECU connector (LIN2 terminal) and body earth.
OK: System voltage

Q. Is the check result normal?
Replace the Lighting control sensor.
Go to Step 6.

STEP 6. Check of short to power supply, short to earth, and open circuit in LIN2 line between ETACS-ECU connector and lighting control sensor connector.

Q. Is the check result normal?
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction .)
Repair the wiring harness.