With Navigation

DTC Troubleshooting: B1776

DTC B1776: Microphone input/output shorted to ground (with navigation)

NOTE:

- Check the vehicle battery condition first Battery Test.
- Check the connectors for poor connections or loose terminals.

1. Check for HFL DTCs.

Is DTC B1776 indicated?

YES -

The failure is duplicated, go to step 2.

NO -

Intermittent failure, the system is OK at this time.

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

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

4. Disconnect the HandsFreeLink control unit 32P connector.

5. Check for continuity between body ground and HandsFreeLink control unit 32P connector terminals No. 15 and No. 16 individually.





Is there continuity?

YES -

There is a short to body ground in the wire(s) between the HandsFreeLink control unit and the HFL-navigation microphone. Replace the affected shielded harness.

NO -

Go to step 6.

6. Check for continuity between HandsFreeLink control unit 32P connector terminals No. 14 and No. 15, and No. 15 and No. 16.





Is there continuity?

YES -

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

NO -

Go to step 7.

7. Remove the audio-navigation unit Audio-Navigation Unit Removal/Installation (With Navigation), and disconnect audio-navigation unit connector D (20P).

NOTE: Eject any audio discs before removing the audio-navigation unit to prevent damaging the CD player's load mechanism.

8. Check for continuity between body ground and HandsFreeLink control unit 32P connector terminals No. 31 and No. 32 individually.





Is there continuity?

YES -

There is a short to body ground in the wires between the HandsFreeLink control unit and the audio-navigation unit. Replace the affected shielded harness.

NO -

Go to step 9.

9. Check for continuity between HandsFreeLink control unit 32P connector terminals No. 31 and No. 32.





Is there continuity?

YES -

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

NO -

Go to step 10.

10. Check for continuity between HandsFreeLink control unit 32P connector terminals No. 31 and No. 32 and audio-navigation unit connector D (20P) terminals No. 19 and No. 20 respectively.





Is there continuity?

YES -

Substitute a known-good HandsFreeLink control unit, and recheck. If the symptom goes away, replace the original HandsFreeLink control unit. If the symptom does not go away, replace the audio-navigation unit Audio-Navigation Unit Removal/Installation (With Navigation).

NO -

There is an open in the wires between the HandsFreeLink control unit and the audio-navigation unit. Replace the affected shielded harness.