INSPECTION PROCEDURE 9: Sometimes 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 may be defective or a failure in the lighting control sensor (rain sensor) adaptation is suspected.

PROBABLE CAUSES

  • Malfunction of the lighting control sensor

  • Lighting control sensor (rain sensor) adaptation failure

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 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. Lighting control sensor (rain sensor) installation surface check
Check that the lighting control sensor (rain sensor) is installed to the windshield glass correctly.

Q. Is the check result normal?
Go to Step 6 after completion of the lighting control sensor (rain sensor) adaptation ().
Install the lighting control sensor (rain sensor) to the windshield glass correctly (Refer to GROUP 54A - Lighting Control Sensor Removal and Installation).

STEP 6. Retest the system.
Check the lighting control sensor (rain sensor) after completion of the lighting control sensor (rain sensor) adaptation
(1) Windshield glass surface should be dry.
(2) Pour water to the windshield glass surface where the lighting control sensor is installed.

Q. Does the windshield wiper operate?
Operate once or more : Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).
Does not operate : Troubleshoot the rain-sensitive wiper function (Refer to Inspection procedure 7 ).