Inspection Procedure 7 [Vehicles With Lighting Control Sensor]
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.
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 Removal and Replacement).
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 Symptom Chart.
STEP 3. Use the scan tool MB991958 to check if an ETACS-related diagnostic trouble code is set.
Connect the scan tool. Reading and Clearing Diagnostic Trouble Codes."
Q. Is the diagnostic trouble code set?
YES Diagnose the ETACS-ECU. Electronic Time and Alarm Control System (ETACS)."
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. Reading and Clearing Diagnostic Trouble Codes."
Q. Is the diagnostic trouble code set?
YES Diagnose the lighting control sensor. [Diagnostic Trouble Code: Headlight) or Service Data ( Scan Tool Testing and Procedures).]
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 (2ohms 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 How to Cope With Intermittent Malfunctions.)
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 How to Cope With Intermittent Malfunctions.)
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 How to Cope With Intermittent Malfunctions.)
NO Repair the wiring harness.