INSPECTION PROCEDURE 7: The Rain Sensitive AUTO Wiper Function Does Not Work At All <Vehicles With Lighting Control Sensor>: Diagnosis

Required Special Tools: 

• MB991223: Harness Set
• MB992006: Extra Fine Probe

1. STEP 1. Lighting control sensor installation surface check 

   Visually check the presence of scratches or air bubbles [diameter of 5 mm (0.2 inch) or more] on the windshield to which the lighting control sensor is installed.

   Q: Is the check result normal? 

   YES:  Go to Step  2.

   NO:  Replace the windshield (Refer to REMOVAL AND INSTALLATION ).

2. STEP 2. Windshield wiper operation check 

   Check that the windshield wipers work normally.

   Q: Is the check result normal? 

   YES:  Go to Step  3.

   NO:  Refer to TROUBLE SYMPTOM CHART  .

3. STEP 3. Using scan tool (M.U.T.-IIISE), read the ETACS-ECU DTC. 

   Check if DTC is set in the ETACS-ECU.

   Q: Is the DTC set? 

   YES:  Troubleshoot the ETACS (Refer to DIAGNOSTIC TROUBLE CODE CHART ).

   NO:  Go to Step  4.

4. STEP 4. Using scan tool (M.U.T.-IIISE), read the lighting control sensor DTC. 

   Check if a lighting control sensor-related DTC is set in the LIN.

   Q: Is the DTC set? 

   YES:  Diagnose the lighting control sensor (Refer to DIAGNOSTIC TROUBLE CODE CHART or Data List Reference Table DATA LIST REFERENCE TABLE  ).

   NO:  Go to Step  5.

5. STEP 5. Resistance measurement at lighting control sensor connector 
   1. Disconnect the connector, and measure the resistance at the wiring harness.
   2. Measure the resistance between lighting control sensor connector (ground terminal) and body ground.

      OK: Continuity exists (2 ohms or less) 

   Q: Is the check result normal? 

   YES:  Go to Step  7.

   NO:  Go to Step  6.

6. STEP 6. Check of open circuit in body ground line between lighting control sensor connector and the body ground. 

   Q: Is the check result normal? 

   YES:  Intermittent malfunction (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTIONS ).

   NO:  Repair the connector(s) or wiring harness.

7. STEP 7. Voltage measurement at lighting control sensor connector (BUP1 terminal). 
   1. Disconnect the connector, and measure the voltage at the wiring harness side.
   2. Measure the voltage between the lighting control sensor connector (BUP1 terminal) and body ground.

      OK: Battery positive voltage 

   Q: Is the check result normal? 

   YES:  Go to Step  9.

   NO:  Go to Step  8.

8. STEP 8. Check of open circuit in BUP1 line between ETACS-ECU and lighting control sensor connector. 

   Q: Is the check result normal? 

   YES:  Intermittent malfunction (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTIONS ).

   NO:  Repair the connector(s) or wiring harness.

9. STEP 9. 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 ground.

      OK: Battery positive voltage 

   Q: Is the check result normal? 

   YES:  Replace the Lighting control sensor.

   NO:  Go to Step  10.

10. STEP 10. Check of short to power supply, short to ground and open circuit in LIN2 line between ETACS-ECU connector and lighting control sensor connector. 

    Q: Is the check result normal? 

    YES:  Intermittent malfunction (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTIONS ).

    NO:  Repair the connector(s) or wiring harness.