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), or press the engine start/stop button to select the OFF mode, then back to ON (II), or the ON mode.

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), or press the engine start/stop button to select the OFF mode.

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 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 wires 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. 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 to body ground 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 front HFL-navigation-ANC/active sound control microphone 7P connector.

12. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.

13. Do the HFL Self-Diagnostic Function.

Do you hear the message "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 front HFL-navigation-ANC/active sound control microphone Front HFL-Navigation-ANC/Active Sound Control Microphone Removal / Installation, and recheck. If the symptom/indication goes away, replace the original front HFL-navigation-ANC/active sound control microphone Front HFL-Navigation-ANC/Active Sound Control Microphone Removal / Installation. If the symptom/indication is still present, replace the HandsFreeLink control unit Service and Repair.