Inspection Procedure 4

INSPECTION PROCEDURE 4: Rear washer does not work normally.

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 windshield and rear washer motor to be turned on.

TECHNICAL DESCRIPTION (COMMENT)

If the rear washer does not work normally, the windshield and rear washer motor, the column switch (windshield wiper and washer switch) or the ETACS-ECU may be defective.

TROUBLESHOOTING HINTS

- The windshield and rear washer motor may be defective
- The column switch (windshield wiper, washer switch) may be defective
- The ETACS-ECU may be defective


DIAGNOSIS

Required Special Tools:

- MB991223: Harness Set
- MB992006: Extra Fine Probe
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: Vehicles communication interface (V.C.I.)
- MB991827: M.U.T.-III USB cable
- MB991911: M.U.T.-III Main harness B

STEP 1. Verify the windshield washers.

Q. Does the windshield washers operate?

YES Go to Step 2.
NO Refer to Inspection Procedure 7 "Windshield washer does not work. Inspection Procedure 10."
STEP 2. Verify the rear wiper.

Q. Does the rear wiper operate?

YES Go to Step 3.
NO Refer to Inspection Procedure 1 "Rear wiper does not work. Inspection Procedure 1."
STEP 3. Use the scan tool MB991958 to check if an ETACS-related diagnostic trouble code is set.





Connect the scan tool. Reading and Clearing Diagnostic Trouble Codes."

Q. Is the diagnostic trouble code set?

YES Diagnose the ETACS-ECU. Electronic Time and Alarm Control System (ETACS).

NO Go to Step 4.

STEP 4. Check the input signal related to the rear washer operation.

- Ignition switch: ACC
- Rear washer switch: ON





OK: Normal condition is displayed.


Q. Is the check result normal?

NO Go to Step 5.
YES Symptom Chart.
STEP 5. Check the washer motor.

(1)Disconnect the washer motor connector A-54.

(2)Fill the windshield washer tank with washer fluid.





(3)When battery voltage is applied between terminals 1 and 2, washer fluid should spray out.

Q. Does the washer motor operate normally?

YES Go to Step 6.

NO Replace the washer motor. Verify that the rear washer works normally.

STEP 6. Replace the ETACS-ECU, and then check its operation.

Replace the ETACS-ECU, and then check that the rear washer works normally.

(1)Replace the ETACS-ECU.

(2)Ignition switch: ON

(3)The rear washer should now work normally.

Q. Is the check result satisfactory?

YES Intermittent malfunction. How to Cope With Intermittent Malfunctions.
NO Replace the front-ECU.