Inspection Procedure 7: The rain sensitive AUTO wiper function does not work at all.


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 lighting control 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)
  • Malfunction of the lighting control sensor
  • Defective windshield wiper motor
  • Malfunction of ETACS-ECU
  • Damaged wiring harness and connectors

DIAGNOSIS 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. Connector check: D-02 Lighting control sensor connector

Q. Is the check result normal?
Go to Step 6.
Repair the damaged connector.

STEP 6. Resistance measurement at the D-02 lighting control sensor connector
(1)Disconnect the connector, and measure the resistance at the wiring harness.
(2)Measure the resistance between D-02 lighting control sensor connector terminal No.2 and body earth.
OK: Continuity exists (2 Ω or less)

Q. Is the check result normal?
Go to Step 8.
Go to Step 7.

STEP 7. Check the wiring harness between D-02 lighting control sensor connector terminal No.2 and body earth.

  • Check the earth wires for open circuit.

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.

STEP 8. Voltage measurement at the D-02 lighting control sensor connector
(1)Disconnect the connector, and measure the voltage at the wiring harness side.
(2)Measure the voltage between D-02 lighting control sensor connector terminal No.1 and body earth.
OK: Battery voltage

Q. Is the check result normal?
Go to Step 10.
Go to Step 9.

STEP 9. Check the wiring harness between D-02 lighting control sensor connector terminal No.1 and fusible link (36)<4A9>,<4B1> or (38)<BWC>.
note Prior to the wiring harness inspection, check intermediate connector C-130, ETACS-ECU connectors C-307 and C-317, and repair if necessary.

  • Check the power supply line for open circuit.

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.

STEP 10. Connector check: C-316 ETACS-ECU connector

Q. Is the check result normal?
Go to Step 11.
Repair the damaged connector.

STEP 11. Measure the voltage at the C-316 ETACS-ECU connector.
(1)Disconnect the connector, and measure the voltage at the wiring harness side.
(2)Measure the voltage between C-316 ETACS-ECU connector terminal No. 1 and body earth.
OK: Battery voltage

Q. Is the check result normal?
Replace the Lighting control sensor.
Go to Step 12.

STEP 12. Check the wiring harness between C-316 ETACS-ECU connector terminal No.1 and D-02 lighting control sensor connector terminal No.3.

  • Check the input and output lines for open or short circuit.

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.