B1776

DTC Troubleshooting: B1776

DTC B1776:

Microphone input/output shorted to ground or open

NOTE: If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN system diagnosis test mode A Troubleshooting - B-CAN System Diagnosis Test Mode A.

1. Connect the HDS to the DLC Reading and Clearing Diagnostic Trouble Codes.

2. Clear the DTCs with the HDS.

3. Turn the ignition switch to LOCK (0) and then back to ON (II).

4. Check for DTCs with the HDS.

Is DTC B1776 indicated?

YES -

Go to step 5.

NO -

Intermittent failure, the system is OK at this time.�

5. Turn the ignition switch to LOCK (0).

6. Disconnect the ambient light (HFL-navigation microphone) 10P connector and the HandsFreeLink 28P connector from the HandsFreeLink control unit.

7. Check for continuity between body ground and HandsFreeLink control unit 28P connector terminals No. 13 and No. 14 individually, then between terminals No. 12 and No. 13.





Is there continuity?

YES -

There is a short in the wire(s) between the HandsFreeLinks control unit and the ambient light (HFL-navigation microphone). Replace the affected shielded harness.�

NO -

Go to step 8.

8. Check for continuity between HandsFreeLink control unit 28P connector terminals No. 13, and No. 14 and ambient light (HFL-navigation microphone) 10P connector terminals No. 7, and No. 8 respectively.





Is there continuity?

YES -

Go to step 9.

NO -

There is an open in the wire(s) between the HandsFreeLinks control unit and the ambient light (HFL-navigation microphone). Replace the affected shielded harness.�

9. Disconnect navigation unit connector C (16P).

10. Check for continuity between HandsFreeLink control unit 28P connector terminal No. 27 and body ground.





Is there continuity?

YES -

Repair a short in the wire between the HandsFreeLinks control unit and the navigation unit.�

NO -

Go to step 11.

11. Check for continuity between HandsFreeLink control unit 28P connector terminal No. 27 and navigation unit connector C (16P) terminal No. 8.





Is there continuity?

YES -

Substitute a known-good HandsFreeLink control unit Service and Repair, and recheck. If the symptom/indication goes away, replace the original HandsFreeLink control unit Service and Repair. If the symptom/indication does not go away, replace the faulty navigation unit Service and Repair.�

NO -

Repair an open in the wire between the HandsFreeLink control unit and the navigation unit.�