Inspection Procedure 2

INSPECTION PROCEDURE 2: The windshield wipers do not work when the wiper switch is at the "INT", "Washer" or "Mist"
position. However, the wipers work at low speed when the switch is at the "Lo" or "Hi" position.






TECHNICAL DESCRIPTION (COMMENT)

This system may be at fail-safe mode if the LIN communication line is defective.
If the system cannot receive any signal from the column switch (windshield wiper and washer switch) due to a open circuit in the LIN communication line or other reasons, the system will enter the fail-safe mode when the ignition switch is at the "ACC" position.

TROUBLESHOOTING HINTS

- The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector
- The column switch may be defective
- The ETACS-ECU may be defective
- The LIN bus line may be defective

DIAGNOSIS

Required Special Tools:

- MB991223: Harness Set
- MB992006: Extra Fine Probe
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: M.U.T.-III USB Cable
- MB991910: M.U.T.-III Main Harness A

STEP 1. 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 2.

STEP 2. Using scan tool MB991958, check data list.

Check the input signal related to the windshield wiper operation.

- Ignition switch: ACC
- Operate the windshield wiper switch at each switch position.





OK: Normal condition is displayed.


Q. Is the check result normal?

YES Go to Step 3.
NO Troubleshoot the ETACS-ECU. Refer to ETACS, Diagnosis - Inspection Procedure 12
"ETACS-ECU does not receive any signal from the column switch signal." Symptom Chart.
STEP 3. Retest the system.

Check that the windshield wipers work normally.

Q. Is the check result normal?

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