Inspection Procedure 4

INSPECTION PROCEDURE 4: Windshield Wipers do not work normally.

Windshield Wiper Power Supply Circuit (Part 1):

Windshield Wiper Power Supply Circuit (Part 2):

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 column switch 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. 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. Trouble Symptom Chart

NO: Go to Step 2.

STEP 2. Using scan tool MB991958, check data list.
Check the input signal related to the windshield wiper operation.
- Ignition switch: ACC
- Operate the windshield wiper switch at each switch position.







OK: Normal condition is displayed.

Q: Is the check result normal?

YES: Go to Step 3.

NO: Troubleshoot the ETACS-ECU. Refer to ETACS, Diagnosis - Inspection Procedure 12 "ETACS-ECU does not receive any signal from the column switch signal".

STEP 3. Check that the windshield wipers work.
Check that the windshield wipers work at high speed and the mist mode.

Q: Is the check result normal?

YES: Go to Step 4.

NO: Go to Step 10.

STEP 4. Check windshield wiper motor connector A-06 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is windshield wiper motor connector A-06 in good condition?

YES: Go to Step 5.

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 5. Check the windshield wiper motor.

1. Disconnect windshield wiper motor connector A-06.







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 6.

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

STEP 6. Measure the voltage at windshield wiper motor connector A-06

1. Disconnect the connector, and measure the voltage at the wiring harness side.
2. Ignition switch: ACC
3. windshield wiper switch: LO







4. Measure the voltage between A-06 windshield wiper motor connector terminal No. 3 and body ground.

OK: Battery positive voltage

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

YES: Intermittent malfunction (Refer to general (body and chassis) - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction).

NO: Go to Step 7.

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 operates normally when the windshield wiper switch is moved to each position.

STEP 8. Check the wiring harness between windshield wiper motor connector A-06 (terminals 1) and ETACS-ECU connector C-304 (terminals 6).

- Check the output lines for open or short circuit.

Q: Is the wiring harness between windshield wiper motor connector A-06 (terminals 1) and ETACS-ECU connector C-304 (terminals 6) in good condition?

YES: Go to Step 9.

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.

STEP 9. Retest the system.
Check that the windshield wipers work normally by moving the switch to each position.

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: Replace the ETACS-ECU.

STEP 10. Check the A-06 windshield wiper motor connector

Q: Is the check result normal?

YES: Go to Step 11.

NO: Repair the connector concerned.

STEP 11. Check the windshield wiper motor.

1. Disconnect windshield wiper motor connector A-06.







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 12.

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

STEP 12. Measure the voltage at the A-06 windshield wiper motor connector.

1. Disconnect the connector, and measure the voltage at the wiring harness side.
2. Ignition switch: ACC
3. Windshield wiper switch: HI,MIST







4. Measure the voltage between A-06 windshield wiper motor connector terminal No.4 and body ground.

OK: Battery positive voltage

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: Go to Step 13.

STEP 13. 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 14.

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 14. Check the wiring harness wires between C-304 ETACS-ECU connector terminal No. 5 and A-06 windshield wiper motor connector terminal No.4.

- Check the output lines for open or short circuit.

Q: Is the check result normal?

YES: Go to Step 15.

NO: Repair the wiring harness.

STEP 15. Retest the system.
Check that the windshield wipers work normally by moving the switch to each position.

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: Replace the ETACS-ECU.