Diagnosis Item 20: Diagnose when the M.U.T.-III cannot receive the data sent by hands free-ECU


caution When servicing a CAN bus line, earth yourself by touching a metal object such as an unpainted water pipe. If you fail to do, a component connected to the CAN bus line may be broken.








FUNCTION



TROUBLE JUDGMENT CONDITIONS



TROUBLESHOOTING HINTS



  • Malfunction of the connector [joint connector (CAN1), hands free-ECU connector improperly connected]
  • Malfunction of the wiring harness [open circuit between the hands free-ECU connector and the joint connector (CAN1), power supply circuit to the hands free-ECU]
  • Malfunction of the hands free-ECU

DIAGNOSIS PROCEDURE

STEP 1. Connector check: C-105 joint connector (CAN1) and C-122 hands free-ECU connector
caution The strand end of the twist wire should be within 10 cm from the connector. For details refer to .

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

STEP 2. Check the wiring harness between C-122 hands free-ECU connector and C-105 joint connector (CAN1)
caution Strictly observe the specified wiring harness repair procedure. For details refer to .
(1)Disconnect hands free-ECU connector and joint connector (CAN1), and check the following wiring harness.
(2)Check that there is continuity between C-122 hands free-ECU connector terminal No.4 and C-105 joint connector (CAN1) terminal No.7 <LHD - CAN_H>
OK: Continuity exists (2 Ω or less)
(3)Check that there is continuity between C-122 hands free-ECU connector terminal No.4 and C-105 joint connector (CAN1) terminal No.11 <RHD - CAN_H>
OK: Continuity exists (2 Ω or less)
(4)Check that there is continuity between C-122 hands free-ECU connector terminal No.16 and C-105 joint connector (CAN1) terminal No.20 <LHD - CAN_L>
OK: Continuity exists (2 Ω or less)
(5)Check that there is continuity between C-122 hands free-ECU connector terminal No.16 and C-105 joint connector (CAN1) terminal No.24 <RHD - CAN_L>
OK: Continuity exists (2 Ω or less)

Q. Is the check result normal?
Check the power supply circuit of the hands free-ECU. Refer to Group 54A - Hands free system- Troubleshooting .
Repair the wiring harness.