With Navigation

DTC Troubleshooting: B1776

DTC B1776: Microphone Input/Output Short to Ground (with navigation system)

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. Initial Inspection and Diagnostic Overview

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 front HFL-navigation-ANC/active sound control microphone 7P connector.

7. Disconnect the HandsFreeLink control unit 28P connector.

8. 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 HandsFreeLink control unit and the front HFL-navigation-ANC/active sound control microphone. Replace the affected shielded harness.

NO - Go to step 9.






9. Check for continuity between HandsFreeLink control unit 28P connector terminals No. 13 and No. 14 and front HFL-navigation-ANC/active sound control microphone 7P connector terminals No. 3 and No. 1 respectively.

Is there continuity?
YES - Go to step 10.

NO - There is an open in the wire(s) between the HandsFreeLink control unit and the front HFL-navigation-ANC/active sound control microphone. Replace the affected shielded harness.






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

11. Check for continuity between body ground and HandsFreeLink control unit 28P connector terminals No. 27 and No. 28 individually.

Is there continuity?
YES - There is a short in the wire(s) between the HandsFreeLink control unit and the navigation unit. Replace the affected shielded harness.

NO - Go to step 12.






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

Is there continuity?
YES - Substitute a known-good HandsFreeLink control unit, Service and Repair and recheck. If the symptom goes away, replace the original HandsFreeLink control unit. If the symptom does not go away, replace the navigation unit. Service and Repair

NO - There is an open in the wire(s) between the HandsFreeLink control unit and the navigation unit. Replace the affected shielded harness.