B1776

DTC Troubleshooting: B1776

DTC B1776: Microphone Input/Output Short to Ground/Open

1. Clear the DTCs with the HDS.

2. Turn the ignition switch to LOCK (0), then turn it to ON (II).

3. Check for DTCs with the HDS.

Is DTC B1776 indicated?
YES - Go to step 4.

NO - Intermittent failure, the system is OK at this time.


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

5. Disconnect the HandsFreeLink control unit 28P connector.

6. Disconnect the HFL-navigation microphone 3P connector.

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

Is there continuity?
YES - Short to body ground in the wire(s) between HandsFreeLink control unit and HFL-navigation microphone. Replace the affected shielded harness.

NO - Go to step 8.






8. Check for continuity between HandsFreeLink control unit the 28P connector terminal No. 13 and No. 14.

Is there continuity?
YES - Short in the wire(s) between HandsFreeLink control unit and HFL-navigation microphone. Replace the affected shielded harness.

NO - Go to step 9.






9. Disconnect navigation unit connector D (12P).

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

Is there continuity?
YES - Short to body ground in the wire(s) between the HandsFreeLink control unit and the navigation unit. Replace the affected shielded harness.

NO - Substitute a known-good navigation unit Service and Repair, then recheck. If the symptom goes away, replace the original navigation unit.