With Navigation

DTC Troubleshooting: B1776

DTC B1776:

Microphone Input/Output Shorted to Ground (with navigation)

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.

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 HFL-navigation microphone 7P connector.

7. Disconnect the HandsFreeLink control unit 28P connector.

8. Check for continuity between HandsFreeLink control unit 28P connector terminal No. 13 and body ground, 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 HFL-navigation microphone. Replace the affected shielded harness.

NO -

Go to step 9.

9. Disconnect audio-navigation unit connector H (28P).

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





Is there continuity?

YES -

There is a short in the wire between the HandsFreeLink control unit and the audio-navigation unit. Replace the affected shielded harness.

NO -

Go to step 11.

11. Reconnect the HandsFreeLink control unit 28P connector and the HFL-navigation microphone 7P connector.

12. Turn the ignition switch to ON (II).

13. Do the HFL Self-Diagnostic Function.

Do you hear, "The hands free system is OK"?

YES -

Substitute a known-good audio-navigation unit (including the HDD) Audio-Navigation Unit Removal/Installation, and recheck. If the symptom/indication goes away, replace the original audio-navigation unit Audio-Navigation Unit Removal/Installation.

NO -

Substitute a known-good HFL-navigation microphone HFL-Navigation Microphone Removal / Installation, and recheck. If the symptom/indication goes away, replace the original HFL-navigation microphone HFL-Navigation Microphone Removal / Installation. If the symptom/indication is still present, replace the HandsFreeLink control unit Service and Repair.