INSPECTION PROCEDURE 8: 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
- STEP 1. Lighting control sensor installation surface check
Visually check the presence of scratches or air bubbles [diameter of 5 mm (0.20 in) 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 WINDSHIELD REMOVAL AND INSTALLATION ).
- 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 .
- 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.
- 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. [Diagnostic Trouble Code: (Refer to DIAGNOSTIC TROUBLE CODE CHART ) or service data (DATA LIST REFERENCE TABLE ).]
- NO: Go to Step 5.
- STEP 5. Connector check: C-316 ETACS-ECU connector
Q: Is the check result normal?
- YES: Go to Step 6.
- NO: Repair the damaged connector.
- STEP 6. Measure the voltage at the C-316 ETACS-ECU connector.
- Disconnect the connector, and measure the voltage at the wiring harness side.
- Measure the voltage between C-316 ETACS-ECU connector terminal No. 1 and body ground.
OK: Battery positive voltage
Q: Is the check result normal?
- YES: Replace the Lighting control sensor.
- NO: Go to Step 7.
- STEP 7. 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?
- YES: Intermittent malfunction (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION ).
- NO: Repair the wiring harness.