Inspection Procedure 9
INSPECTION PROCEDURE 9: Sometimes the rain sensitive AUTO wiper function works even though there is no rainfall [ Vehicles with lighting control sensor].CAUTION: Whenever ECU is replaced, ensure that the input and output signal circuits are normal.
TECHNICAL DESCRIPTION (COMMENT)
The lighting control sensor may be defective or a failure in the lighting control sensor (rain sensor) adaptation is suspected.
TROUBLESHOOTING HINTS
- Malfunction of the lighting control sensor
- Lighting control sensor (rain sensor) adaptation failure
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 (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 body - 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. 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 chassis electrical ETACS, "How to connect the scan tool (M.U.T.-III)".
Q: Is the diagnostic trouble code set?
YES : Diagnose the ETACS-ECU. Refer to chassis electrical ETACS, "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 chassis electrical ETACS, "How to connect the scan tool (M.U.T.-III)".
Q: Is the diagnostic trouble code set?
YES : Diagnose the lighting control sensor. [Diagnosis Code: (Refer to chassis electrical - Diagnosis Code Chart) or service data.]
NO : Go to Step 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.
NO : Install the lighting control sensor (rain sensor) to the windshield glass correctly (Refer to chassis electrical - Lighting control sensor removal and Installation).
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 general (body and chassis) - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction).
Does not operate : Troubleshoot the rain sensitive wiper function (Refer to Inspection procedure 7). Inspection Procedure 7