B1776

Control System DTCs

DTC Troubleshooting: B1776

DTC B1776 : Microphone Input/Output Shorted to Ground

NOTE:
* Check the vehicle battery condition first Component Tests and General Diagnostics.
* Before you troubleshoot, make sure to follow the How to Troubleshoot the HandsFreeLink System. How To Troubleshoot The HandsFreeLink System
* Check the connectors for poor connections or loose terminals.

1. Problem verification:

-1. Check for HFL DTCs . How To Troubleshoot The HandsFreeLink System

Is DTC B1776 indicated?
-YES- The failure is duplicated, go to step 2.
-NO- Intermittent failure, the system is OK at this time.

2. Shorted wire check (MIC+ line):

-1. Turn the ignition switch to LOCK (0).

-2. Disconnect the following connectors.






-3. Check for continuity between test points 1 and 2.










Is there continuity?
-YES- There is a short to body ground in the wire between the HandsFreeLink control unit and the HFL microphone. Replace the affected shielded harness.
-NO- The MIC+ wire is not shorted to ground. Go to step 3.

3. Shorted wire check (MIC+ line to another lines):

-1. Check for continuity between test points 1 and 2.














Is there continuity?
-YES- There is a short in the wires between the HandsFreeLink control unit and the HFL microphone. Replace the affected shielded harness.
-NO- The MIC+ wire is OK. Go to step 5.
-NO- The MIC+ wire is OK. Go to step 4.

4. HandsFreeLink control unit check:

-1. Substitute a known-good HFL microphone Service and Repair, and recheck.

Does the symptom/indication go away?
-YES- Replace the original HFL microphone.
-NO- Replace the HandsFreeLink control unit Service and Repair.

5. Shorted wire check (HFT-NAVI MIC+ line):

-1. Disconnect the following connector.






-2. Check for continuity between test points 1 and 2.










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- The HFT-NAVI MIC+ wire is not shorted to ground. Go to step 6.

6. Shorted wire check (HFT-NAVI MIC+ line to another lines):

-1. Check for continuity between test points 1 and 2.














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- The HFT-NAVI MIC+ wire is OK. Go to step 7.

7. Determine possible failure area (audio-navigation unit, others):

-1. Reconnect the HandsFreeLink control unit 32P connector and the HFL microphone 3P connector.

-2. Turn the ignition switch to ON (II).

-3. Do the HFL Self-Diagnostic Function. HandsFreeLink System Self-Diagnostic Function

Do you hear, "The HFT is OK"?
-YES- Replace the audio-navigation unit Audio-Navigation Unit Removal and Installation.
-NO- Go to step 8.

8. HandsFreeLink control unit check:

-1. Turn the ignition switch to LOCK (0).

-2. Substitute a known-good HFL microphone Service and Repair, and recheck.

Does the symptom/indication go away?
-YES- Replace the original HFL microphone.
-NO- Replace the HandsFreeLink control unit Service and Repair.