INSPECTION PROCEDURE G-1: The windshield wipers does not work at all.


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


COMMENTS ON TROUBLE SYMPTOM
The windshield wiper motor, the column switch or the front-ECU may be defective. If a problem is found in the ECU check by using the SWS monitor, also check the wiper backup circuit (between C-301 column switch connector terminal No.8 and A-15X front-ECU connector terminal No.26) and repair if necessary.

POSSIBLE CAUSES

  • Malfunction of the windshield wiper motor
  • 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 ON 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 Inspection Procedure A-2 "Communication with the column switch (column-ECU) is not possible ."
"NG" is displayed on the "FRONT ECU" menu. : Refer to Inspection Procedure A-4 "Communication with the front-ECU is not possible ."

Step 2. Function diagnosis by using the SWS monitor.
Check the SWS communication signal, which are related to the windshield wiper function.
<Selected item> F.WIPER INT
  • Turn the ignition switch to the ACC position.
  • Windshield wiper switch: INT
Item No.
 Item name
 Normal condition
Item 05
 INT WIPER SW
 ON
Item 31
 IGNITION SW ACC
 ON
Item 70
 FRONT ECU ACK
 NORMAL ACK or HI-BEAM ACK
OK: Normal conditions are displayed for all the items.

Q. Are the check result normal?
Normal conditions displayed for all the items : Go to Step 3.
Normal condition is not displayed for item No.05 : Replace the column switch.
Normal condition is not displayed for item No.31 : Refer to inspection procedure P-1 "The ignition switch (ACC) signal is not received ."
Normal condition is not displayed for item No.70 : Replace the front-ECU.

Step 3. Connector check: A-01 windshield wiper motor connector.

Q. Is the check result normal?

Go to Step 4.

Repair the connector.

Step 4. Check the windshield wiper motor assembly.
Refer to GROUP 51 - Windshield wiper .

Q. Is the check result normal?
Go to Step 5
Replace the windshield wiper motor assembly.

Step 5. Resistance measurement at the A-01 windshield wiper motor connector.

(1)Disconnect the connector, and measure at the wiring harness side.

(2)Continuity between A-01 windshield wiper motor connector terminal No.2, and body earth
OK: 2Ω or less

Q. Is the check result normal?

Go to Step 8.

Go to Step 6.

Step 6. Connector check: A-40 earth connector.

Q. Is the check result normal?

Go to Step 7.

Repair the connector.

Step 7. Check the wiring harness between A-01 windshield wiper motor connector terminal No.2 to A-40 earth connector terminal No.5.


  • Check the earth wires for open circuit.

Q. Is the check result normal?

The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).

Repair the wiring harness.

Step 8. Connector check: A-15X front-ECU connector.

Q. Is the check result normal?

Go to Step 9.

Repair the connector.

Step 9. Voltage measurement at the A-15X front-ECU connector.

(1)Remove the front-ECU, and measure at the relay box side.
(2)Ignition switch: ACC

(3)Check the voltage between the A-15X front-ECU connector terminal No.24 and body earth.
OK: System voltage

Q. Is the check result normal?

Go to Step 11.

Go to Step 10.

Step 10. Check the wiring harness between A-15X front-ECU connector terminal No.24 to the ignition switch (ACC).



note Prior to the wiring harness inspection, check the junction block connectors C-202, C-203 and intermediate connector C-125 and repair if necessary.

  • Check the power supply line to the ignition switch (ACC) for open circuit.

Q. Is the check result normal?

The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).

Repair the wiring harness.

Step 11. Retest the system.
The windshield wiper should now work normally at all.

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.