Inspection Procedure 4: Your voice is not transferred during a call: Diagnosis

Required Special Tools 

• MB991223: Wiring harness set
• MB992006: Extra fine probe

1. STEP 1. Confirm that the vehicle is parked properly. 

   Check that the vehicle is parked in an open area.

   Q: Is the check result normal? 

   YES:  Go to Step  2.

   NO:  Move the vehicle to an open area. Then go to Step  2.

2. STEP 2. Check test mode. 

   Execute "Test report" in the test mode (Refer to ON-VEHICLE SERVICE  ).

   Q: Is the check result normal? 

   YES:  Go to Step  3.

   NO:  Troubleshoot the TCU. Refer to INSPECTION PROCEDURE 8 "SOS EMERGENCY ASSIST/INFORMATION ASSIST DOES NOT CONNECTED. (IT CAN START THE CALLING TO THE TELEMATICS CALL CENTER)"  .

3. STEP 3. Using scan tool (M.U.T.-IIISE), check the special function. 

   Check the microphone (Refer to SPECIAL FUNCTION TABLE  ).

   Test 

   • Item No. 5: Microphone check (Door speaker)

   OK: Your voice is played (during the test). 

   Q: Is the check result normal? 

   YES:  The trouble can be an intermittent malfunction (Refer to How to use Troubleshooting/inspection Service Points - HOW TO COPE WITH INTERMITTENT MALFUNCTION ).

   NO:  Go to Step  4.

4. STEP 4. Using the smartphone link display audio, check for the microphone unit. 

   Using the multivision display diagnosis mode, check if the "Communication Check" (Refer to Smartphone Link Display Audio - Diagnosis, DIAGNOSIS MODE <Up to 20 Model year> or DIAGNOSIS MODE <From 22 Model year>).

   Q: Is the check result normal? 

   YES:  Replace the TCU (Refer to TCU  ).

   NO:  Go to Step  5.

5. STEP 5. Resistance measurement at the TCU connector (MI+ terminals). 
   1. Disconnect the TCU connector, and measure at the wiring harness side.
   2. Check the resistance between the TCU connector (MI+ terminal) and the microphone unit connector (terminal No. 1).

      OK: The resistance should be 2 ohms or less 

   3. Check the resistance between the TCU connector (MI+ terminal) and body ground.

      OK: No continuity 

   4. Check the resistance between the TCU connector (MI+ terminal) and the microphone unit connector (except terminal No. 2).

      OK: No continuity 

      Q: Is the check result normal? 

      YES:  Replace the microphone unit (Refer to ON-VEHICLE SERVICE ). Then go to Step  6.

      NO:  Repair the connector(s) or wiring harness.

6. STEP 6. Retest the system. 

   Q: Is the check result normal? 

   YES:  The procedure is complete.

   NO:  Replace the TCU (Refer to TCU  ).