1. Wipers Do Not Work At All, Washer is OK
CIRCUIT OPERATION
A signal from the 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 switch input circuit system, harness wire or connector, windshield wiper motor, backup circuit or FRONT-ECU may be faulty.
TROUBLESHOOTING HINTS
The most likely causes for this case:
- Malfunction of the column switch
- Damaged wiring harness and connector
- Malfunction of the windshield wiper motor
- Malfunction of the FRONT-ECU
DIAGNOSIS
Required Special Tool:
MB991502: Scan Tool (MUT-II)
STEP 1. Check a diagnostic trouble code.
CAUTION: To prevent damage to scan tool MB991502, make sure the ignition switch is "OFF" before connecting or disconnecting the scan tool.
Connect scan tool MB991502 to the data link connector, and then check the diagnostic trouble code.
If code 12 is displayed on scan tool MB991502, replace the column switch. Then go to Step 6.
If code 13 is displayed on scan tool MB991502, replace the FRONT-ECU. Then go to Step 6.
If no diagnostic trouble code is displayed, go to Step 2.
STEP 2. Check the windshield wiper motor.
Check the wiper motor after disconnecting the wiring harness connector A-02 with the wiper motor still installed on the body.
Wiper Motor at Low-Speed and High-Speed Operation
Connect a battery to the wiper motor as shown in the illustration and check the motor operation at low-speed and high-speed.
If the windshield wiper motor is damaged, replace the wiper motor. Then go to Step 3.
If the windshield wiper motor is not damaged, go to Step 3.
STEP 3. Check the harness wire between the FRONT-ECU connector A-09X and column switch connector C-60.
1. Remove the FRONT-ECU.
2. Remove the column cover.
3. Check the harness wire between the FRONT-ECU connector A-09X and column switch connector C-60.
If the harness wire between the FRONT-ECU connector A-09X and column switch connector C-60 is damaged, repair the wire.
Then go to Step 4.
NOTE: After checking intermediate connector C-66, check the wire. If intermediate connector C-66 is damaged, repair or replace it. Refer to Harness Connector Inspection. Then go to Step 4.
STEP 4. Check the harness wires between windshield wiper motor connector A-02 and FRONT-ECU connector A-09X.
If any harness wire between windshield wiper motor connector A-02 and FRONT-ECU connector A-09X is damaged, repair it.
Then go to Step 5.
If the harness wires are normal, go to Step 5.
NOTE: After checking intermediate connector C-05, check the wire. If intermediate connector C-05 is damaged, repair or replace it. Refer to Harness Connector Inspection.
Then go Step 5.
STEP 5. Check the harness wire between windshield wiper motor connector A-02 and ground.
If the harness wire between windshield wiper motor connector
A-02 and ground is damaged, repair it. Then go to Step 6.
STEP 6. Check symptoms.
Confirm that the intermediate connectors, the harness wires, the column switch, the FRONT-ECU and the windshield wiper motor are normal.