Part 1 of 2

TROUBLE SYMPTOM CHART

Trouble Symptom Chart:

SYMPTOM PROCEDURES

GENERAL DESCRIPTION CONCERNING THE WIPER AND WASHER

The following ECU's affect the functions and control of the wiper and washer.






General circuit diagram for the wiper and washer

<Windshield Wiper And Washer>:

<Rear Wiper And Washer>:

INSPECTION PROCEDURE 1: The windshield wipers do not work at all.

Windshield Wiper Power Supply Circuit (Part 1):

Windshield Wiper Power Supply Circuit (Part 2):

CIRCUIT OPERATION
The windshield wiper and washer switch sends a signal through the column-ECU (incorporated in the column switch) to the ETACS-ECU. If the column-ECU sends a windshield wiper and washer switch "ON" signal to the ETACS-ECU, the ETACS-ECU turns on the relay (incorporated in the ETACS-ECU), thus causing the windshield wiper and washer motor to be turned on.

If the LIN communication line is defective, the ETACS-ECU operates windshield wiper motor by using the other communication lines (wiper backup circuit) instead of that line. In this case, the windshield wiper works at low speed regardless of the windshield wiper and washer switch positions ("LO" or "HIGH").

TECHNICAL DESCRIPTION (COMMENT)
If the windshield wiper does not work at all, the windshield wiper motor, column switch (windshield wiper and washer switch) or the ETACS-ECU may be defective.

TROUBLESHOOTING HINTS
Trouble in input signal system .
The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector.
The wiper motor may be defective.
The column switch may be defective.
The ETACS-ECU may be defective.

DIAGNOSIS

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. Use the scan tool MB991958 to check if an ETACS-related diagnostic trouble code is set.






Connect the scan tool.

Q: Is the diagnostic trouble code set?

YES : Diagnose the ETACS-ECU.


NO : Go to Step 2.

STEP 2. Check the input signal related to the windshield wiper operation.
Ignition switch ACC






OK: Normal condition is displayed.

Q: Is the check result normal?

NO : Go to Step 3.

YES : Refer to ETACS, Input signal procedures.

STEP 3. Check windshield wiper motor connector A-08 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is windshield wiper motor connector A-08 in good condition?

YES : Go to Step 4.

NO : Repair or replace the damaged component(s). Refer to General (Electrical), Harness Connector Inspection. Verify that the windshield wiper works normally.

STEP 4. Check the windshield wiper motor.
1. Disconnect windshield wiper motor connector A-08.






2. Connect a battery to the windshield wiper motor as shown. Then check that the windshield wiper motor operates normally at high and low speeds.

Q: Does the windshield wiper motor operate normally?

YES : Go to Step 5.

NO : Replace the windshield wiper motor. Verify that the windshield wiper works normally.

STEP 5. Check the ground circuit to the windshield wiper motor. Measure the resistance at the windshield wiper motor connector A-08.
1. Disconnect windshield wiper motor connector A-08 and measure the resistance available at the wiring harness side of the connector.






2. Measure the resistance value between terminal 5 and ground.
The resistance should be 2 Ohms or less.

Q: Is the measured resistance 2 Ohms or less?

YES : Go to Step 7.

NO : Go to Step 6.

STEP 6. Check the wiring harness between windshield wiper motor connector A-08 (terminals) and ground.

Q: Is the wiring harness between windshield wiper motor connector A-08 (terminals) and ground in good condition?

YES : No action is necessary and testing is complete.

NO : The wiring harness may be damaged or the connector (s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary. Verify the windshield wiper works normally.

STEP 7. Check ETACS-ECU connector C-304 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is ETACS-ECU connector C-304 in good condition?

YES : Go to Step 8.

NO : Repair or replace the damaged component(s). Refer to General (Electrical), Harness Connector Inspection. Verify that the windshield wiper works normally.

STEP 8. Measure the voltage at ETACS-ECU connector C-304.
1. Disconnect ETACS-ECU connector C-304 and measure the resistance available at the wiring harness side of the connector.






2. Measure the voltage between terminal 1 and ground.
The voltage should measure approximately 12 volts (battery positive voltage).

Q: Is the measured voltage approximately 12 volts (battery positive voltage)?

YES : Go to Step 10.

NO : Go to Step 9.

STEP 9. Check the wiring harness between ETACS-ECU connector C-309 (terminal 1) and the fusible link (34).
Check the power supply line for open circuits.

Q: Is the wiring harness between ETACS-ECU connector C-309 (terminal 1) and the fusible link (34) in good condition?

YES : Intermittent malfunction. Refer to General (Body and Chassis), How to cope with intermittent malfunction.

NO : Repair or replace the damaged component(s). Refer to General (Electrical), Cables and wire check.

STEP 10. Check the wiring harness between ETACS-ECU connector C-304 (terminals 5, 6) and windshield wiper motor connector A-308 (terminals 1, 4).
Check the input and output lines for open or short circuit.

Q: Is the wiring harness between ETACS-ECU connector C-304 (terminals 5, 6) and windshield wiper motor connector A-308 (terminals 1, 4) in good condition?

YES : Go to Step 11.

NO : Repair or replace the damaged component(s). Refer to General (Electrical), Cables and wire check.

STEP 11. Retest the system.
Check that the windshield wipers work normally.

Q: Is the check result normal?

YES : Intermittent malfunction. Refer to General (Body and Chassis), How to cope with intermittent malfunction.

NO : Replace the ETACS-ECU.

INSPECTION PROCEDURE 2: The windshield wipers do not work when the wiper switch is at the "INT", "Washer" or "Mist" position. However, the wipers work at low speed when the switch is at the "Lo" and "Hi" position.

Windshield Wiper Motor Circuit:

TECHNICAL DESCRIPTION (COMMENT)
This system may be at fail-safe mode if the LIN communication line is defective.
If the system cannot receive any signal from the column switch (windshield wiper and washer switch) due to a open circuit in the LIN communication line or other reasons, the system will enter the fail-safe mode when the ignition switch is at the "ACC" position.

TROUBLESHOOTING HINTS
The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector.
The column switch may be defective.
The ETACS-ECU may be defective.
The LIN bus line may be defective.

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. Use the scan tool MB991958 to check if an ETACS-related diagnostic trouble code is set.






Connect the scan tool.

Q: Is the diagnostic trouble code set?

YES : Diagnose the ETACS-ECU.

NO : Go to Step 2.

STEP 2. Retest the system.
Check that the windshield wipers work normally.

Q: Is the check result normal?

YES : Intermittent malfunction. Refer to General (Body and Chassis), How to cope with intermittent malfunction.

NO : Replace the ETACS-ECU.

INSPECTION PROCEDURE 3: Windshield wipers do not stop at the specified park position.

Windshield Wiper Automatic Stop Relay Circuit:

TECHNICAL DESCRIPTION (COMMENT)
If the windshield wipers do not stop at predetermined park position, the windshield wiper motor or the ETACS-ECU may be defective.

TROUBLESHOOTING HINTS
The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector.
The windshield wiper motor may be defective.
The ETACS-ECU may be defective.

DIAGNOSIS

Required Special Tools:
MB991223: Harness Set
MB992006: Extra Fine Probe

STEP1. Check windshield wiper motor connector A-08 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is windshield wiper motor connector A-08 in good condition?

YES : Go to Step 2.

NO : Repair or replace the damaged component(s). Refer to General (Electrical), Harness Connector Inspection. Verify that the windshield wiper works normally.

STEP 2. Check the windshield wiper motor.
1. Disconnect windshield wiper motor connector A-08.






2. Connect the vehicle battery to the windshield wiper motor connector as shown, and operate the windshield wiper at low speed. While the windshield wiper is working, disconnect the battery at positions other than the specified park position to stop the windshield wiper motor.
3. When the battery is connected as shown, the motor should run at low speed, and then stop at the specified park position.

Q: Does the windshield wiper motor operate normally?

YES : Go to Step 3.

NO : Replace the windshield wiper motor. The windshield wiper should now stop at the specified park position.

STEP 3. Check the fusible link (34) circuit to the windshield wiper motor. Measure the voltage at windshield wiper motor connector A-08.
1. Disconnect windshield wiper motor connector A-08 and measure the voltage available at the wiring harness side of the connector.






2. Turn the ignition switch to the "ACC" position.
3. Measure the voltage between terminal 2 and ground.
The voltage should measure approximately 12 volts (battery positive voltage).

Q: Is the measured voltage approximately 12 volts (battery positive voltage)?

YES : Go to Step 5.

NO : Go to Step 4.

STEP 4. Check the wiring harness between windshield wiper motor connector A-08 (terminal 2) and the fusible link (34).
Check the power supply line for open circuits.

Q: Is the wiring harness between windshield wiper motor connector A-08 (terminal 2) and the fusible link (34) in good condition?

YES : Intermittent malfunction. Refer to General (Body and Chassis), How to cope with intermittent malfunction.

NO : Repair or replace the damaged component(s). Refer to General (Electrical), Cables and wire check.

STEP 5. Check ETACS-ECU connector C-304 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is ETACS-ECU connector C-304 in good condition?

YES : Go to Step 6.

NO : Repair or replace the damaged component(s). Refer to General (Electrical), Harness Connector Inspection.

STEP 6. Check the wiring harness between ETACS-ECU connector C-304 (terminals a, 12) and windshield wiper motor connector A-08 (terminals 2, 3).
Check the output lines for open or short circuits.

Q: Is the wiring harness between ETACS-ECU connector C-304 (terminals a, 12) and windshield wiper motor connector A-08 (terminals 2, 3) in good condition?

YES : Go to Step 7.

NO : Repair or replace the damaged component(s). Refer to General (Electrical), Cables and wire check.

STEP 7. Retest the system.
Check that the windshield wipers stops at the specified park position.

Q: Is the check result normal?

YES : Intermittent malfunction. Refer to General (Body and Chassis), How to cope with intermittent malfunction.

NO : Replace the ETACS-ECU.

INSPECTION PROCEDURE 4: Windshield Wipers do not work normally.

Windshield Wiper Motor Drive Circuit:

TECHNICAL DESCRIPTION (COMMENT)
If either of the windshield wiper switch positions is defective, the windshield wiper motor, column switch (windshield wiper and washer switch) or the ETACS-ECU may be defective.

TROUBLESHOOTING HINTS
Trouble in input signal system
The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector
The wiper motor may be defective
The ETACS-ECU may be defective

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. Use the scan tool MB991958 to check if an ETACS-related diagnostic trouble code is set.






Connect the scan tool.

Q: Is the diagnostic trouble code set?

YES : Diagnose the ETACS-ECU.

NO : Go to Step 2.

STEP 2. Check the input signal related to the windshield wiper operation.
ignition switch ACC






OK: Normal condition is displayed.

Q: Is the check result normal?

NO : Go to Step 3.

YES : Refer to ETACS, Input signal procedures.

STEP 3. Check windshield wiper motor connector A-08 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is windshield wiper motor connector A-08 in good condition?

YES : Go to Step 4.

NO : Repair or replace the damaged component(s). Refer to General (Electrical), Harness Connector Inspection. Verify that the windshield wiper operates normally when the windshield wiper switch is moved to each position.

STEP 4. Check the windshield wiper motor.
1. Disconnect windshield wiper motor connector A-08.






2. Connect a battery to the windshield wiper motor as shown.
Then check if the windshield wiper motor operates normally at high and low speeds.

Q: Does the windshield wiper motor operate normally?

YES : Go to Step 5.

NO : Replace the windshield wiper motor. Verify that the windshield wiper operates normally when the windshield wiper switch is moved to each position.

STEP 5. Check ETACS-ECU connector C-304 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is ETACS-ECU connector C-304 in good condition?

YES : Go to Step 6.

NO : Repair or replace the damaged component(s). Refer to General (Electrical), Harness Connector Inspection. Verify that the windshield wiper operates normally when the windshield wiper switch is moved to each position.

STEP 6. Check the wiring harness between windshield wiper motor connector A-08 (terminals 1 and 4) and ETACS-ECU connector C-304 (terminals 5 and 6).

Q: Is the wiring harness between windshield wiper motor connector A-08 (terminals 1 and 4) and ETACS-ECU connector C-304 (terminals 5 and 6) in good condition?

YES : No action is necessary and testing is complete.

NO : The wiring harness may be damaged or the connector (s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary. Verify that the windshield wiper operates normally when the windshield wiper switch is moved to each position.

INSPECTION PROCEDURE 5: The windshield intermittent wiper interval cannot be adjusted by operating the windshield intermittent wiper volume control switch.

Windshield Intermittent Wiper Control Circuit:

TECHNICAL DESCRIPTION (COMMENT)
If the windshield intermittent wiper interval is not changed by operating the windshield intermittent wiper interval adjusting knob or according to the vehicle speed, the column switch or the ETACS-ECU may be defective.

TROUBLESHOOTING HINTS
Trouble in input signal system
The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector
The ETACS-ECU may be defective

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. Use the scan tool MB991958 to check if an ETACS-related diagnostic trouble code is set.






Connect the scan tool.

Q: Is the diagnostic trouble code set?

YYES : Diagnose the ETACS-ECU.

NO : Go to Step 2.

STEP 2. Check the ETACS configuration function.
Use the ETACS configuration function to check that "Front wiper operation" is set to "variable INT" or "vehicle speed dependent".

Q: Is the check result normal?

YES : Go to Step 3.

NO : Use the ETACS configuration function to set "Front wiper operation" to "variable INT" or "vehicle speed dependent".

STEP 3. Retest the system.
Check that the windshield wiper interval changes when the windshield wiper volume control is rotated.

Q: Is the check result normal?

YES : Intermittent malfunction. Refer to General (Body and Chassis), How to cope with intermittent malfunction.

NO : Replace the ETACS-ECU.

INSPECTION PROCEDURE 6: The windshield intermittent wiper interval is not changed according to the vehicle speed.

Windshield Intermittent Wiper Control Circuit:

TECHNICAL DESCRIPTION (COMMENT)
If the intermittent wiper interval does not depend on the vehicle speed, the input circuit of the vehicle speed signal and the ETACS-ECU may be defective. Alternatively, the vehicle speed-dependent wiper may be set to "disabled" by using the configuration function.

TROUBLESHOOTING HINTS
The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector
The CAN bus line may be defective
The ETACS-ECU may be defective

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. Retest the system.
Check that the windshield intermittent wiper interval can be adjusted by operating the windshield intermittent wiper volume control switch.

Q: Is the check result normal?

YES : Go to Step 2.

NO : Refer to Inspection Procedure 5 "The windshield intermittent wiper interval cannot be adjusted by operating the windshield intermittent wiper volume control switch".

STEP 2. Check the ETACS configuration function.
Use the ETACS configuration function to confirm that "FRONT WIPER OPERATION" is set to "VEHICLE SPEED DEPENDENT".

Q: Is the check result normal?

YES : Go to Step 3.

NO : Use the ETACS configuration function to set "FRONT WIPER OPERATION" to "VEHICLE SPEED DEPENDENT".

STEP 3. Use the scan tool MB991958 to diagnose the CAN bus lines.






Connect the scan tool.

Q: Is the check result normal?

YES : Go to Step 4.

NO : Repair the CAN bus line.

STEP 4. Use the scan tool MB991958 to diagnose other system diagnostic trouble code

Connect the scan tool.

Check that the TCM sets a diagnostic trouble code.

Q: Is the diagnostic trouble code set?

YES : Diagnose the TCM.

NO : Go to Step 5.

STEP 5. Retest the system.
Check that the intermittent wiper interval depends on the vehicle speed.

Q: Is the check result normal?

YES : Intermittent malfunction. Refer to General (Body and Chassis), How to cope with intermittent malfunction.

NO : Replace the ETACS-ECU.