Inspection Procedure C-8: The windshield intermittent wiper volume signal is not received.


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










COMMENTS ON TROUBLE SYMPTOM
The intermittent wiper interval is calculated in accordance with the input signal from the windshield intermittent wiper volume. If this signal is abnormal, the wiper interval cannot be adjusted.

PROBABLE CAUSES

  • Malfunction of the wiper/washer switch
  • Malfunction of the ETACS-ECU
  • Damaged harness wires and connectors

DIAGNOSIS PROCEDURE

STEP 1. Connector check: D-311 column switch connector

Q. Is the check result normal?
Go to Step 2.
Repair the defective connector.

STEP 2. Resistance measurement at D-311 column switch connector.
(1)Disconnect the connector, and measure at the column switch side.
(2)Resistance between D-311 column switch connector terminal No.6 and body earth
OK: The resistance should rise from 0 to 1 kΩ when the windshield intermittent wiper volume is rotated from "Fast" to "Slow".

Q. Is the check result normal?
Go to Step 3.
Replace the wiper/washer switch.

STEP 3. Connector check: D-420 ETACS-ECU connector

Q. Is the check result normal?
Go to Step 4.
Repair the defective connector.

STEP 4. Check the wiring harness between D-311 column switch connector terminal No.6 and D-420 ETACS-ECU connector terminal No.66.

  • Check the input line for open and short circuit.

Q. Is the check result normal?
Go to Step 5.
Repair the wiring harness.

STEP 5. Retest the system.
Check that the windshield intermittent wiper volume is sending a correct signal.

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 ETACS-ECU.