Inspection Procedure G-4

Rear Wiper and Washer: Rear Washer does not Operate

Rear Washer Drive Circuit:

Connector:

NOTE: This troubleshooting requires use of scan tool MB991502 and SWS monitor kit MB991862. For details of how to use the SWS monitor, refer to "How to use SWS monitor".


CIRCUIT OPERATION
The rear washer switch sends a signal through the column-ECU (incorporated in the column switch) to the ETACS-ECU. If the column-ECU sends a rear washer switch "ON" signal to the ETACS-ECU, the ETACS-ECU turns on the relay (incorporated in the ETACS-ECU), thus causing the rear washer motor to be turned on.

TECHNICAL DESCRIPTION (COMMENT)
If the rear washer does not work normally, 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 washer switch)
- Malfunction of the ETACS-ECU

DIAGNOSIS

Required Special Tools:
- MB991223: Test Harness Set
- MB991502: Scan Tool (MUT-II)
- MB991862: SWS monitor kit

STEP 1. Check the rear wiper.

Q: Does the rear wiper operate?

YES: Go to STEP 2.

NO: Refer to Inspection Procedure G-1 "Rear wiper does not work at all."

STEP 2. Check the input signal by using service data of the SWS monitor.

Set each switch to the following condition before checking input signals from the rear washer switch:
- ignition switch: ACC
- rear washer switch: ON









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. Also connect SWS monitor kit MB991862 after turning on scan tool MB991502.

1. Connect scan tool MB991502 to the data link connector.
2. Connect SWS monitor kit MB991862 to the column switch connector.




3. Select "REAR WIPER - REAR WIPER" (FUNCTION DIAG.), and check that normal conditions are displayed on the items described in the table.

Q: Is normal conditions displayed "REAR WASH.SW"?

YES: Go to STEP 3.

NO: Refer to Inspection Procedure L-6 "ETACS-ECU does not receive a signal from the rear washer switch."




STEP 3. Check the rear washer motor.

1. Disconnect rear washer motor connector A-23.
2. Fill the washer tank with washer fluid.
3. When battery voltage is applied between terminals 1 and 2, washer fluid should gush out.

Q: Does the rear washer motor operate normally?

YES: Go to Step 4.

NO: Replace the rear washer motor. Check that the rear washer works normally.




STEP 4. Check at rear washer motor connector A-23 to check the rear washer motor ground circuit
1. Disconnect rear washer motor connector A-23, and measure at the wiring harness side.
2. Measure the resistance value between terminal 1 and ground.
- The measured value should be 2 Ohm or less.

Q: Does the measured resistance value correspond with this range?

YES: Go to Step 7.

NO: Go to Step 5.




STEP 5. Check rear washer motor connector A-23 for damage.

Q: Is rear washer motor connector A-23 in good condition?

YES: Go to Step 6.

NO: Repair or replace the connector. Refer to Harness Connector Inspection. Check that the rear washer works normally.




STEP 6. Check the wiring harness between rear washer motor connector A-23 and ground.

Q: Is the wiring harness between rear washer motor connector A-23 and ground in good condition?

YES: No action to be taken.

NO: Repair the wiring harness. Check that the rear washer works normally.







STEP 7. Check rear washer motor connector A-23 and ETACS-ECU connector C-227 for damage.

Q: Are rear washer motor connector A-23 and ETACS-ECU connector C-227 in good condition?

YES: Go to Step 8.

NO: Repair or replace the connector. Refer to Harness Connector Inspection. Check that the rear washer works normally.










STEP 8. Check the wiring harness between rear washer motor connector A-23 and ETACS-ECU connector C-227.

NOTE: Also check intermediate connector C-111. If intermediate connectors C-111 is damaged, repair or replace the connector as described in Harness Connector Inspection.

Q: Is the wiring harness between rear washer motor connector A-23 and ETACS-ECU connector C-227 in good condition?

YES: Replace the ETACS-ECU. Check that the rear washer works normally.

NO: Repair the wiring harness. Check that the rear washer works normally.