INSPECTION PROCEDURE G-1: Windshield Wiper and Washer: Windshield wiper does not operate.: Diagnosis
Required Special Tools:
- MB991223: Test Harness Set
- MB991502: Scan Tool (MUT-II)
- MB991529: Diagnostic Trouble Code Check Harness
- STEP 1. Check method of the input signal
Q: Which is to be used, the scan tool or a voltmeter to check the input signal?
Scan tool MB991502 : Go to Step 2.
Voltmeter : Go to Step 3.
- STEP 2. Check the input signal (by using scan tool MB991502).
Check the input signals from the windshield wiper switches.
CAUTION: To prevent damage to scan tool MB991502, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502.- Connect scan tool MB991502 to the data link connector.
- Check that the tone alarm of scan tool MB991502 sounds when the input signal enters.
Q: Does the tone alarm of scan tool MB991502 sounds when the input signal enters?
YES : Go to Step 4.
NO: Scan tool MB991502 does not sound when the windshield wiper switch is turned from "OFF" to "MIST", "INT", "LO" or "HIGH": Refer to INSPECTION PROCEDURE O-15 "THE WINDSHIELD MIST WIPER SWITCH, WINDSHIELD INTERMITTENT WIPER SWITCH, WINDSHIELD LOW-SPEED WIPER SWITCH, WINDSHIELD HIGH-SPEED WIPER SWITCH OR WINDSHIELD WASHER SWITCH SIGNAL IS NOT SENT TO THE ETACS-ECU ."
- STEP 3. Check the input signal (by using a voltmeter).
Check the input signals from the windshield wiper switches.
- Use special tool MB991529 to connect a voltmeter between ground terminal 4 or 5 and ETACS-ECU terminal 9 of the data link connector.
- Check that the voltmeter indicator deflects once when the input signal enters.
Q: Does the voltmeter indicator deflect?
YES : Go to Step 4.
NO: The voltmeter needle does not fluctuate when the windshield wiper switch is turned from "OFF" to "MIST", "INT", "LO" or "HIGH": Refer to INSPECTION PROCEDURE O-15 "THE WINDSHIELD MIST WIPER SWITCH, WINDSHIELD INTERMITTENT WIPER SWITCH, WINDSHIELD LOW-SPEED WIPER SWITCH, WINDSHIELD HIGH-SPEED WIPER SWITCH OR WINDSHIELD WASHER SWITCH SIGNAL IS NOT SENT TO THE ETACS-ECU ."
- STEP 4. Check the windshield wiper motor.
- Disconnect the windshield wiper motor connector A-03.
- Connect a battery to the windshield wiper motor as shown. Then check the windshield wiper motor operates normally at high and low speeds. See Fig 3.
Q: Is the wiper motor in good condition?
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. Test at the windshield wiper motor connector A-03.
- Disconnect windshield wiper motor connector A-03 and measure the resistance available at the wiring harness side of the connector.
- 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 8.
NO: Go to Step 6.
- STEP 6. Check windshield wiper motor connector A-03 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Is windshield wiper motor connector A-03 in good condition?
YES : Go to Step 7.
NO: Repair or replace the damaged component(s). Refer to , HARNESS CONNECTOR INSPECTION . Verify that the windshield wiper works normally.
- STEP 7. Check the wiring harness between windshield wiper motor connector A-03 (terminal 5) and ground.
Q: Is the wiring harness between windshield wiper motor connector A-03 (terminal 5) and ground in good condition?
YES : No action is necessary and testing is complete.
NO: The wiring harness may be damaged or the connector 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 works normally.
- STEP 8. Check the ignition switch (ACC) circuit to the front-ECU. Test at front-ECU connector A-11X.
- Disconnect front-ECU connector A-11X and measure the voltage available at the relay box side of the connector.
- Turn the ignition switch to "ACC" position.
- Measure the voltage between terminal 24 and ground.
- The voltage should measure approximately 12 volts (battery positive voltage).
Q: Is the measured voltage approximately 12 volts (battery positive voltage)?
YES : Replace the front-ECU. The windshield wiper should work normally.
NO: Go to Step 9.
- STEP 9. Check the front-ECU connector A-11X for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Is front-ECU connector A-11X in good condition?
YES : Go to Step 10.
NO: Repair or replace the damaged component(s). Refer to , HARNESS CONNECTOR INSPECTION . Verify that the windshield wiper works normally.
- STEP 10. Check the wiring harness between front-ECU connector A-11X (terminal 24) and the ignition switch (ACC).
NOTE: Also check intermediate connector C-209, junction block connectors C-311 and C-312 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector C-209, junction block connector C-311 or C-312 is damaged, repair or replace the damaged component(s) as described in , HARNESS CONNECTOR INSPECTION .
Q: Is the wiring harness between front-ECU connector A-11X (terminal 24) and the ignition switch (ACC) in good condition?
YES : No action is necessary and testing is complete.
NO: The wiring harness may be damaged or the connector 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 works normally.