Inspection Procedure G-2

Windshield Wiper Motor Driver Circuit:

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 the input signal.
Check the input signals from the windshield wiper switch.






CAUTION: To prevent damage to scan tool MB991502, always turn the ignition switch to "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.





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.
If a defect appears, check the windshield wiper switch input circuit. Refer to Inspection Procedure O-18.
If no defect appears, go to Step 2.




STEP 2. 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.
If the wiper motor is damaged, replace the wiper motor. The windshield wiper should work normally when the windshield wiper switch is set to all positions.
If the wiper motor is in good condition, go to Step 3.







STEP 3. Check the wiper motor connector A-03 and front-ECU connector A-09X for damage.
If the wiper motor connector A-03 and front-ECU connector A-09X are damaged, 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.
If the connectors are in good condition, go to Step 4.










STEP 4. Check the harness wires between wiper motor connector A-03 and front-ECU connector A-09X.

NOTE: After checking intermediate connector C-06, check the wires. If intermediate connector C-06 is damaged, repair or replace it. Refer to Harness Connector Inspection.

If the harness wires between wiper motor connector A-03 and front-ECU connector A-09X are damaged, repair them. The windshield wiper should work normally when the windshield wiper switch is set to all positions.