Inspection Procedure G-2

Windshield wiper and washer: Any of the windshield wiper switch positions is defective.

Windshield Wiper Motor Drive Circuit
- Refer to Inspection Procedure G-1.

CIRCUIT OPERATION
A signal from the windshield wiper switch is sent through the column-ECU inside the column switch to the front-ECU. The signal turns on the relay inside the front-ECU to operate the wiper motor.

TECHNICAL DESCRIPTION (COMMENT)
The wiper motor, column switch (windshield wiper and washer switch) or the front-ECU may be defective.

TROUBLESHOOTING HINTS
- Malfunction of the wiper motor
- Malfunction of the column switch (windshield wiper and washer switch)
- Malfunction of the front-ECU
- Damaged harness wires and connectors

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 the 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.




1. Connect scan tool MB991502 to the data link connector.
2. Check that the tone alarm of scan tool MB991502 sounds when the input signal enters.

Q: Does the tone alarm of scan tool MB991502 sound when the input signal enters?

YES: Go to Step 4.
NO: Check the windshield wiper switch input circuit. Refer to Inspection Procedure O-16.

STEP 3. Check the input signal (by using a voltmeter).
Check the input signals from the windshield wiper switches.




1. Use special tool MB991529 to connect a voltmeter between ground terminal 4 or 5 and ETACS-ECU terminal 9 of the data link connector.
2. Check that the voltmeter indicator deflects once when the input signal enters.

Q: Does the voltmeter indicator deflect?

YES: Go to Step 4.
NO: Check the windshield wiper switch input circuit. Refer to Inspection Procedure O-16.




STEP 4. Check the windshield wiper motor.
1. Disconnect the wiper motor connector A-03.
2. Connect a battery to the wiper motor as shown in the illustration and check motor operation at low-speed and high-speed.

Q: Is the wiper motor in good condition?

YES: Go to Step 5.
NO: Replace the wiper motor. The windshield wiper should work normally when the windshield wiper switch is set to all positions.







STEP 5. Check the wiper motor connector A-03 and front-ECU connector A-09X for damage.

Q: Are wiper motor connector A-03 and front-ECU connector A-09X in good condition?

YES: Go to Step 6.
NO: Repair or replace them. Refer to Harness Connector Inspection. The windshield wiper should work normally when the windshield wiper switch is set to all positions.










STEP 6. Check the harness wires between wiper motor connector A-03 and front-ECU connector A-09X.

NOTE: After checking intermediate connector C-05, check the wires. If intermediate connector C-05 is damaged, repair or replace it. Refer to Harness Connector Inspection.

Q: Are the harness wires between wiper motor connector A-03 and front-ECU connector A-09X in good condition?

YES: There is no action to be taken.
NO: Repair them. The windshield wiper should work normally when the windshield wiper switch is set to all positions.