Inspection Procedure 13: The rain sensitive AUTO wiper function does not work at all <Vehicles with LDW camera (rain sensor)>.


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

OPERATION
The raindrops sensitive wiper function automatically adjusts the wiping speed of windscreen wiper by detecting the rainfall through LDW-ECU (rain sensor) when the ignition switch is in the ON position and the column switch is in the AUTO position.

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

PROBABLE CAUSES

  • Defective column switch (column-ECU)
  • Defective windshield wiper motor
  • Malfunction of ETACS-ECU
  • Malfunction of LDW-ECU (rain sensor)
  • Damaged wiring harness and connectors

DIAGNOSTIC PROCEDURE

STEP 1. LDW camera (rain sensor) mounting surface check
Visually check the presence of scratches or air bubbles (diameter of 5 mm or more) on the windshield to which the LDW camera (rain 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. Check whether the LDW camera (rain sensor) is mounted correctly.
Check whether the LDW camera is securely installed to the windshield glass.

Q. Is the check result normal?
Go to Step 3.
Reinstall the LDW camera to the windshield glass correctly. (Refer to GROUP 54A - LDW camera removal and installation ), and initialise the LDW camera (rain sensor). (Refer to GROUP 54A - How to initialise LDW camera .)

STEP 3. Windshield wiper operation check
Check that the windshield wipers work normally.

Q. Is the check result normal?
Go to Step 4.
Refer to trouble symptom chart .

STEP 4. M.U.T.-III diagnosis code
Check whether the LDW-ECU (rain sensor)-related diagnosis code is set.

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

STEP 5. 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 6.

STEP 6. M.U.T.-III data list
Use the LDW-ECU service data to check the signals related to the on/off status of the rain sensor.

  • Turn the wiper switch to the AUTO position.
Item No.
 Item name
 Normal conditions
Item 19
 Rain sensor ON/OFF
 ON
OK: Normal condition is displayed.

Q. Is the check result normal?
Go to Step 7.
Diagnose the LDW-ECU (rain sensor). (Refer to GROUP 54A - Diagnosis Code Chart .)

STEP 7. M.U.T.-III data list
Use the LDW-ECU service data to check the signals related to the operation of the automatic wiper function.

  • Turn the wiper switch to the AUTO position.
  • When a mist of water is sprayed onto the LDW camera mounting surface on the windshield, the wipers should operate at high or low speed.
Item No.
 Item name
 Normal conditions
Item 74
 Wiping stage
 ON
OK: Normal condition is displayed.

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 .)
Go to Step 8.

STEP 8. Check the trouble symptom.
Initialise the LDW camera (rain sensor). (Refer to GROUP 54A - How to initialise LDW camera .)
After the LDW camera (rain sensor) has been initialised, check the system operation according to the procedure below.
(1)Check that the surface of windshield is dry.
(2) Apply water to the LDW camera (rain sensor) sensing portion on the windshield.

Q. Does the wiper work?
Operate : Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction .)
Not operate : Replace LDW-ECU.