Inspeciton Procedure 4: Even when the steering wheel voice-control switch is operated, the conversation is not possible.










FUNCTION


When the steering wheel voice-control switch is operated, the switch signal is transmitted to the audio unit <vehicles without MMCS> or audio visual navigation unit <vehicles with MMCS>. Then, via the CAN communication, the signal is transmitted from the audio unit <vehicles without MMCS> or audio visual navigation unit <vehicles with MMCS> to the hands-free module.

COMMENTS ON TROUBLE SYMPTOM


If the conversation is not possible even when the steering wheel voice-control switch is operated, the steering wheel voice-control switch or audio unit <vehicles without MMCS> or the audio visual navigation unit <vehicles with MMCS> may be defective.

PROBABLE CAUSES



DIAGNOSIS PROCEDURE

STEP 1. Check the steering wheel audio remote control switch.
Check that the audio unit <vehicles without MMCS> or audio visual navigation unit <vehicles with MMCS> can be operated normally using the steering wheel audio remote control switch.

Q. Is the check result normal?
Go to Step 2.
Diagnose the steering wheel audio remote control switch (Refer to Radio and CD player - Diagnosis <vehicles without MMCS> or MMCS - Diagnosis <vehicles with MMCS>).

STEP 2. M.U.T.-III CAN bus diagnostics
Use the M.U.T.-III to diagnose the CAN bus lines.

Q. Is the check result normal?
Go to Step 3.
Repair the CAN bus line (Refer to GROUP 54C - Troubleshooting ).

STEP 3. Check the steering wheel voice-control switch.
Refer to .

Q. Is the check result normal?
Go to Step 4.
Replace the steering wheel voice-control switch.

STEP 4. Check the steering wheel audio remote control switch.
Refer to .

Q. Is the check result normal?
Go to Step 5.
Replace the steering wheel audio remote control switch.

STEP 5. Connector check: C-206 steering wheel voice-control switch connector, C-213 steering wheel audio remote control switch connector

Q. Is the check result normal?
Go to Step 6.
Repair the defective connector.

STEP 6. Check the wiring harness between C-206 steering wheel voice-control switch connector terminal No.3 and C-213 steering wheel audio remote control switch connector terminal No.3.

  • Check the communication lines for open circuit and short circuit.

Q. Is the check result normal?
Go to Step 7.
Repair the wiring harness.

STEP 7. Check the wiring harness between C-206 steering wheel voice-control switch connector terminal No.2 and C-202 clock spring connector terminal No.4.

  • Check the communication lines for open circuit and short circuit.

Q. Is the check result normal?

    Go to Step 8.
Repair the wiring harness.

STEP 8. Retest the system
Check that the hands-free cellular phone system works normally when the steering wheel voice-control switch is operated.

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 audio unit <vehicles without MMCS> or audio visual navigation unit <vehicles with MMCS>.