B1776

DTC Troubleshooting: B1776

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

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. Reading and Clearing Diagnostic Trouble Codes

2. Clear the DTCs with the HDS.

3. Turn the ignition switch to LOCK (0), then turn it 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 HandsFreeLink control unit 28P connector.

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

8. Check for continuity between body ground and HandsFreeLink control unit 28P connector terminals No. 13 and No. 14 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 9.






9. Check for continuity between HandsFreeLink control unit 28P connector terminals No. 13 and No. 14.

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 10.






10. Disconnect audio-navigation unit connector D (12P).

11. 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 - Substitute a known-good audio-navigation unit Audio-Navigation Unit Removal/Installation (With Navigation), then recheck. If the symptom goes away, replace the original audio-navigation unit.