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" and "Hi" position.


caution Whenever the ECU is replaced, ensure that the communication circuit is normal.

COMMENTS ON TROUBLE SYMPTOM
It is assumed that the windshield wipers are in the fail-safe mode due to the LIN bus lines failure.

PROBABLE CAUSES

  • Faulty LIN bus line
  • Malfunction of ETACS-ECU
  • Defective column switch (column-ECU)
  • Malfunctions of the wiring harness and connectors

DIAGNOSTIC PROCEDURE

STEP 1. M.U.T.-III diagnosis code
Check if an ETACS-related diagnosis code is set.

Q. Is the diagnosis code set?
Troubleshoot the ETACS. Refer to GROUP 54A - ETACS .
Go to Step 2.

STEP 2. M.U.T.-III data list
Check the input signal related to the windshield wiper operation.

  • Turn the ignition switch to the ACC position.
  • Operate the windshield wiper switch at each switch position.
Item No.
 Item name
 Windshield wiper switch position
 Normal condition
Item 235

 Front wiper ACT
 LO
 ON
HI
INTO
 ON and OFF
MIST
 ON
Item 236
 Front wiper Lo/Hi
 LO
 OFF
HI
 ON
INTO
 OFF
MIST
 ON
OK: Normal condition is displayed.

Q. Is the check result normal?
YES <Normal conditions are displayed for all items> : Go to Step 3.
NO <Normal condition is not displayed for item Nos. 235 and/or 236> : Troubleshoot the ETACS-ECU. Refer to ETACS, Diagnosis - Inspection Procedure 11 "Column switch signal is not received." .

STEP 3. Retest the system.
Check that the windshield wipers work normally.

Q. Is the check result normal?
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).
Replace the ETACS-ECU.