Inspection Procedure 2: The ignition switch (IG1) signal is not received.


caution Before replacing the ECU, ensure that the power supply circuit, the earth circuit and the communication circuit are normal.






COMMENTS ON TROUBLE SYMPTOM



PROBABLE CAUSES



  • Malfunction of the ignition switch
  • Malfunction of the ETACS-ECU
  • Malfunction of fuse
  • Damaged harness wires and connectors

DIAGNOSIS PROCEDURE

STEP 1. Connector check: C-317 ETACS-ECU connector

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

STEP 2. Voltage measurement at the C-317 ETACS-ECU connector.
(1)Disconnect the connector, and measure at the ETACS-ECU side.
(2)Turn the ignition switch to the ON position.
(3)Measure the voltage between the C-317 ETACS-ECU connector terminal No. 6 and the body earth.
OK: System voltage

Q. Is the check result normal?
Go to Step 4.
Go to Step 3.

STEP 3. Wiring harness check between the C-317 ETACS-ECU connector terminal No. 6 and the ignition switch (IG1)
Check the power supply (IG1) line for open circuit.

Q. Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).
Repair the wiring harness.

STEP 4. M.U.T.-III data list

    Turn the ignition switch to the ON position.
Item No.
 Item name
 Normal condition
Item 254
 IG voltage
 System voltage
OK: Normal condition is displayed.

Q. Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).
Replace the ETACS-ECU.