Inspection Procedure H-4
Rear Washer Does Not WorkRear Washer Motor Drive Circuit:
Connectors:
CIRCUIT OPERATION
A signal from the rear washer switch is sent through the column-ECU inside the column switch to the ETACS-ECU. The signal turns on the relay inside the ETACS-ECU to operate the washer motor.
TECHNICAL DESCRIPTION (COMMENT)
The rear washer motor, the column switch (windshield wiper and washer switch) or the front-ECU may be defective.
TROUBLESHOOTING HINTS
- Malfunction of the rear washer motor
- Malfunction of the column switch (windshield wiper and windshield washer switch)
- Malfunction of the ETACS-ECU
- Damaged harness wires or connectors
DIAGNOSIS
Required Special Tools:
- MB991223: Test Harness Set
- MB991502: Scan Tool (MUT-II)
- MB991529: Diagnostic Trouble Code Check Harness
STEP 1. Check the rear wiper operation.
Q: Does the rear wiper work normally?
YES: Go to Step 2
NO: Solve the problem first.
STEP 2. Check the Input signal (by using scan tool MB991502).
Check the input signal from the rear washer switch:
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 rear washer switch input signal circuit. Refer to Inspection Procedure O-18.
STEP 3. Check the input signal (by using a voltmeter).
Check the input signal from the rear washer switch:
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 rear washer switch input signal circuit. Refer to Inspection Procedure O-18.
STEP 4. Check the rear washer motor.
1. Disconnect rear washer motor connector A-34.
2. Fill the washer tank with water.
3. Check that the water squirts out strongly when battery positive voltage is applied to terminals 1 and 2.
Q: Is the rear washer motor In good condition?
YES: Go to Step 5.
NO: Replace it. The rear washer should work normally
STEP 5. Check the mar washer motor ground circuit at the mar washer motor connector A-34.
1. Disconnect the rear washer motor connector A-34 and measure at the harness side.
2. Measure the resistance between terminal 2 and ground.
Q: Is the resistance less than 2 ohms?
YES: Go to Step 8.
NO: Go to Step 6.
STEP 6. Check the rear washer motor connector A-34 for damage.
Q: Is rear washer motor connector A-34 in good condition?
YES: Go to Step 7.
NO: Repair or replace it. Refer to Harness Connector Inspection. The rear washer should work normally.
STEP 7. Check the harness wire between rear washer motor connector A-34 and ground.
Q: Is the harness wire between rear washer motor connector A-34 and ground in good condition?
YES: There is no action to be taken.
NO: Repair it. The rear washer should work normally.
STEP 8. Check the rear washer motor connector A-34 and ETACS-ECU connector C-114 for damage.
Q: Are rear washer motor connector A-34 and ETACS-ECU connector C-114 In good condition?
YES: Go to Step 9.
NO: Repair or replace them. Refer to Harness Connector Inspection. The rear washer should work normally.
STEP 9. Check the harness wires between rear washer motor connector A-34 and ETACS-ECU connector C-114.
NOTE: After checking intermediate connectors C-94 and junction block connector C-107, check the wires. If intermediate connectors C-94 and junction block connector C-107 are damaged, repair or replace them. Refer to Harness Connector Inspection.
Q: Are the harness wires between rear washer motor connector A-34 and ETACS-ECU connector C-114 in good condition?
YES: Replace the ETACS-ECU. The rear washer should work normally.
NO: Repair them. The rear washer should work normally.