Malfunction of ETACS-ECU power supply circuit


COMMENTS ON TROUBLE SYMPTOM



PROBABLE CAUSES



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

DIAGNOSIS PROCEDURE


STEP 1. Connector check: C-415, C-417 ETACS-ECU connector


Q. Is the check result normal?





STEP 2. Resistance measurement at the C-415 and C-417 ETACS-ECU connector.


(1)Disconnect the connector, and measure at the wiring harness side.
(2)Measure the resistance between the C-415 ETACS-ECU connector terminal No. 17 and the body earth.
OK: Continuity exists (2 Ω or less)
(3)Measure the resistance between the C-417 ETACS-ECU connector terminal No. 15 and the body earth.
OK: Continuity exists (2 Ω or less)

Q. Is the check result normal?





STEP 3. Wiring harness check between the C-415 or C-417 ETACS-ECU connector terminal No. 17 or 15 and the body earth



  • Check the earth wires for open circuit.

Q. Is the check result normal?





STEP 4. Connector check: C-406 and C-408 ETACS-ECU connector


Q. Is the check result normal?





STEP 5. Voltage measurement at the C-406 ETACS-ECU connector.


(1)Disconnect the connector, and measure at the wiring harness side.
(2)Measure the voltage between the C-406 ETACS-ECU connector terminal No. 2 and the body earth.
OK: System voltage

Q. Is the check result normal?





STEP 6. Wiring harness check between the C-406 ETACS-ECU connector terminal No. 2 and the fusible link (36) <petrol> or (38) <diesel>.



  • Check the power supply line for open circuit.

Q. Is the check result normal?





STEP 7. Voltage measurement at the C-407 ETACS-ECU connector.


(1)Disconnect the connector, and measure at the wiring harness side.
(2)Measure the voltage between the C-407 ETACS-ECU connector terminal No. 1 and the body earth.
OK: System voltage

Q. Is the check result normal?





STEP 8. Wiring harness check between the C-407 ETACS-ECU connector terminal No. 1 and the fusible link (34) <petrol> or (44) <diesel>.



  • Check the power supply line for open circuit.

Q. Is the check result normal?





STEP 9. Retest the system



Q. Is the check result normal?