Inspection Procedure 7
INSPECTION PROCEDURE 7: The rain sensitive AUTO wiper function does not work at all [Vehicles with lighting control sensor].CAUTION: Whenever ECU is replaced, ensure that the input and output signal circuits are normal.
Raindrops Sensing Wiper Function Control Circuit (Part 1):
Raindrops Sensing Wiper Function Control Circuit (Part 2):
CIRCUIT OPERATION
When the column switch is in the AUTO position, this function automatically adjusts the wiping speed of windshield wiper by detecting the rain fall through lighting control sensor.
TECHNICAL DESCRIPTION (COMMENT)
The windshield wiper motor, the column switch, the lighting control sensor, the harness connector, or the ETACS-ECU may be defective.
TROUBLESHOOTING HINTS
- 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
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 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 trouble symptom chart. Trouble Symptom Chart
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. [Diagnostic Trouble Code: (Refer to chassis electrical - Diagnostic Trouble Code Chart) or Service Data]
NO: Go to Step 5.
STEP 5. Connector check: D-02 Lighting control sensor connector
Q: Is the check result normal?
YES: Go to Step 6.
NO: 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 ground.
OK: Continuity exists (2 � or less)
Q: Is the check result normal?
YES: Go to Step 8.
NO: Go to Step 7.
STEP 7. Check the wiring harness between D-02 lighting control sensor connector terminal No.2 and body ground.
- Check the ground wires for open circuit.
Q: Is the check result normal?
YES: Intermittent malfunction (Refer to general (body and chassis) - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction)
NO: 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 ground.
OK: Battery positive voltage
Q: Is the check result normal?
YES: Go to Step 10.
NO: Go to Step 9.
STEP 9. Check the wiring harness between D-02 lighting control sensor connector terminal No.1 and fusible link (36).
NOTE: Prior to the wiring harness inspection, check intermediate connector C-133, 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?
YES: Intermittent malfunction (Refer to general (body and chassis) - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction).
NO: Repair the wiring harness.
STEP 10. Connector check: C-316 ETACS-ECU connector
Q: Is the check result normal?
YES: Go to Step 11.
NO: 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 ground.
OK: Battery positive voltage
Q: Is the check result normal?
YES: Replace the Lighting control sensor.
NO: 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?
YES: Intermittent malfunction (Refer to general (body and chassis) - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction).
NO: Repair the wiring harness.