Diagnosis Item 18: 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


If the M.U.T.-III can not communicate with the hands free-ECU, this diagnosis result will be set.

TRUBLE JUDGEMENT CONDITIONS


If a communication flag is not set for the hands free-ECU, the ETACS-ECU determines that there is a failure.

TROUBLESHOOTING HINTS



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 .
Disconnect hands free-ECU connector and joint connector (CAN1), and check the following wiring harness.

  • The wiring harness between C-122 hands free-ECU connector terminal No.4 and C-105 joint connector (CAN1) terminal No.7 <LHD - CAN_H>
  • The wiring harness between C-122 hands free-ECU connector terminal No.4 and C-105 joint connector (CAN1) terminal No.11 <RHD - CAN_H>
  • The wiring harness between C-122 hands free-ECU connector terminal No.16 and C-105 joint connector (CAN1) terminal No.20 <LHD - CAN_L>
  • The wiring harness between C-122 hands free-ECU connector terminal No.16 and C-105 joint connector (CAN1) terminal No.24 <RHD - CAN_L>

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.