Inspection Procedure 2: The windshield wipers do not operate at "INT", "WASHER" or "MIST" position, but operate at "LO" and "HI" position.<Using SWS monitor>
caution Whenever the ECU is replaced, ensure that the input and output signal circuits are normal.

COMMENTS ON TROUBLE SYMPTOM
The system may be at fail-safe mode as the SWS communication line is defective. If the ETACS-ECU does not receive the ignition switch (ACC) signal due to an open circuit in the SWS communication lines or other reasons when the ignition switch is at the ACC position, the system will enter the fail-safe mode.

POSSIBLE CAUSES

  • Malfunction of the column switch
  • Malfunction of the front-ECU
  • Damaged harness wires and connectors

DIAGNOSIS PROCEDURE

Step 1. ECU check by using the SWS monitor.
Check that the power supply and earth lines to the column switch (column-ECU) and the front-ECU and the SWS communication lines are normal.

  • Turn the ignition switch to the ACC position.
ECUS TO BE CHECKED
  • COLUMN ECU
  • FRONT ECU
OK: "OK" are displayed for all the items

Q. Are the check result normal?
"OK" is displayed for all the items : Go to Step 2.
"NG" is displayed on the "COLUMN ECU" menu. : Refer to GROUP 54C - SWS, Inspection Procedure 1 "Communication with the column switch (column-ECU) is not possible ."
"NG" is displayed on the "FRONT ECU" menu. : Refer to GROUP 54C - SWS, Inspection Procedure 3 "Communication with the front-ECU is not possible ."

Step 2. Retest the system.
The windshield wiper should now work normally.

Q. Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).
Replace the front-ECU.