Inspection Procedure 1: The windshield wipers do not work at all.


caution Whenever ECU is replaced, ensure that the input and output signal circuits are normal.

COMMENTS ON TROUBLE SYMPTOM
The windshield wiper motor, the column switch (column-ECU) or ETACS-ECU may be defective. Check the wiper backup circuit (between the column switch WB/U and the ETACS-ECU WB/U), and repair if necessary.

PROBABLE CAUSES

  • Defective windshield wiper motor
  • 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?
Diagnose the ETACS-ECU (Refer to GROUP 54A - ETACS, Trouble Symptom Chart ).
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 288
 ACC switch
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 No. 235> : GROUP 54A - ETACS, Diagnosis - Inspection Procedure 11 "Column switch signal is not received." .
NO <Normal condition is not displayed for item No. 288> : GROUP 54A - ETACS, Diagnosis - Inspection Procedure 1 "The ignition switch (ACC) signal is not received" .

STEP 3. Check the windshield wiper motor.
Check that the windshield wiper motor works normally. Refer to .

Q. Is the check result normal?
Go to Step 4.
Replace the windshield wiper motor.

STEP 4. Measure the resistance at windshield wiper motor connector.
(1)Disconnect the connector, and measure the resistance at the wiring harness.
(2)Measure the resistance between the windshield wiper motor connector earth terminal and body earth.
OK: Continuity exists (2 Ω or less)

Q. Is the check result normal?
Go to Step 6.
Go to Step 5.

STEP 5. Check the wiring harness between windshield wiper motor connector and body earth.

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 ).
Repair the connector(s) or wiring harness.

STEP 6. Measure the voltage at ETACS-ECU connector.
(1)Disconnect the connector, and measure the voltage at the wiring harness side.
(2)Measure the voltage between the ETACS-ECU(+B1 terminal) and the body earth.
OK: System voltage

Q. Is the check result normal?
Go to Step 8.
Go to Step 7.

STEP 7. Check of open in power supply line between fusible link and ETACS(+B terminal).

Q. Is the check result normal?
Intermittent malfunction. Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points, - How to Cope with Intermittent Malfunctions .)
Repair the connector(s) or wiring harness.

STEP 8.Check of open, short circuit in W.LO, HI line between windshield wiper motor connector and ETACS-ECU connector

Q. Is the check result normal?
Go to Step 9.
Repair the connector(s) or wiring harness.

STEP 9. Check the trouble symptom.
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 Malfunctions .)
Replace the ETACS-ECU.