Inspection Procedure 7: Check the hands free-ECU power supply circuit.


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










CIRCUIT OPERATION



  • The power supply to the hands free-ECU is provided by the fusible link (34).
  • If the power supply system from the battery is defective, the system operates by the power supply from the ignition switch (IG1).

TECHNICAL DESCRIPTION (COMMENT)



PROBABLE CAUSES



  • Damaged harness wires and connectors
  • Malfunction of the hands free-ECU

DIAGNOSIS PROCEDURE

STEP 1. Connector check: C-41 hands free-ECU connector

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

STEP 2. Resistance measurement at C-41 hands free-ECU connector.
(1)Disconnect the connector, and measure at the wiring harness side.
(2)Check the continuity between terminal 15 and earth.
OK: Continuity exists (2 Ω or less)

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

STEP 3. Check the wiring harness between C-41 hands free-ECU connector terminal No.15 and body earth.

Q. Is the check result normal?
Replace the hands free-ECU. The system should communicate with the hands free-ECU normally.
Repair the wiring harness.

STEP 4. Check the wiring harness between C-41 hands free-ECU connector terminal No.13 and fusible link (36) <PETROL> or (38) <DIESEL>.
note Prior to the wiring harness inspection, check ETACS-ECU connector C-307 and C-317, and repair if necessary.

Q. Is the check result normal?
Replace the hands free-ECU. The system should communicate with the hands free-ECU normally.
Repair the wiring harness.