INSPECTION PROCEDURE 9: Sometimes The Rain Sensitive AUTO Wiper Function Works Even Though There Is No Rainfall - Vehicles With Lighting Control Sensor: Diagnosis

Required Special Tools: 

• MB991223: Harness Set
• MB992006: Extra Fine Probe
• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
  • MB991824: V.C.I.
  • MB991827: M.U.T.-III USB Cable
  • MB991910: M.U.T.-III Main Harness A

1. STEP 1. Lighting control sensor (rain 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? 

   • 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 INSPECTION PROCEDURE 3  .
3. STEP 3. Use the scan tool MB991958 to check if an ETACS-related diagnostic trouble code is set. 

   Connect the scan tool. Refer to HOW TO CONNECT THE SCAN TOOL (M.U.T.-III) ."

   Q: Is the diagnostic trouble code set? 

   • YES:  Diagnose the ETACS-ECU. Refer to DIAGNOSTIC TROUBLE CODE CHART ."
   • NO:  Go to Step 4.
     Fig 1: Connecting Scan Tool To Data Link Connector

     Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
4. STEP 4. Using scan tool MB991958, read the lighting control sensor diagnostic trouble code. 

   Check if a lighting control sensor diagnostic trouble code is set.

   Connect the scan tool. Refer to HOW TO CONNECT THE SCAN TOOL (M.U.T.-III) ."

   Q: Is the diagnostic trouble code set? 

   • YES:  Diagnose the lighting control sensor. (Refer to DIAGNOSIS CODE CHART or DATA LIST REFERENCE TABLE  ).
   • NO:  Go to Step 5.
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 firmly.

   Q: Is the check result normal? 

   • YES:  Go to Step 6 after completion of the lighting control sensor (rain sensor) adaptation (LIGHTING CONTROL SENSOR  ).
   • NO:  Install the lighting control sensor (rain sensor) to the windshield glass correctly (Refer to LIGHTING CONTROL SENSOR REMOVAL AND INSTALLATION ).
6. STEP 6. Retest the system. 

   Check the lighting control sensor (rain sensor) after completion of the lighting control sensor (rain sensor) adaptation

   1. Check that the windshield glass surface is dry.
   2. Pour the windshield glass surface where the lighting control sensor is installed.

   Q: Does the windshield wiper operate? 

   Operate one or more:  Intermittent malfunction (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTIONS ).

   Does not operate:  Troubleshoot the rain sensitive wiper function (Refer to INSPECTION PROCEDURE 7  ).