B1776

DTC Troubleshooting: B1776

DTC B1776:

Microphone input/output shorted to ground

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 Initial Inspection and Diagnostic Overview.

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 ambient light (HFL-navigation microphone) 10P connector and the HandsFreeLink 28P connector from the HandsFreeLink control unit.

7. Check for continuity between body ground and HandsFreeLink control unit 28P connector the terminals No. 13 and No. 14 individually.





Is there continuity?

YES -

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

NO -

Go to step 8.

8. Check for continuity between the terminals of HandsFreeLink control unit 28P connector according to the table.









Is there continuity between any of the terminals?

YES -

There is a short in the wire(s) between the HandsFreeLink control unit and the ambient light (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 and ambient light (HFL-navigation microphone) 10P connector terminals No. 7, and No. 8 respectively.





Is there continuity?

YES -

Go to step 10.

NO -

There is an open in the wire(s) between the HandsFreeLinks control unit and the ambient light (HFL-navigation microphone). Replace the affected shielded harness.

10. Disconnect navigation unit connector C (16P).

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





Is there continuity?

YES -

Repair a short in the wire between the HandsFreeLinks control unit and the navigation unit.

NO -

Go to step 12.

12. Check for continuity between HandsFreeLink control unit 28P connector terminal No. 27 and navigation unit connector C (16P) terminal No. 8.





Is there continuity?

YES -

Substitute a known-good HandsFreeLink control unit Testing and Inspection, and recheck. If the symptom/indication goes away, replace the original HandsFreeLink control unit Testing and Inspection. If the symptom/indication does not go away, replace the faulty navigation unit Service and Repair.

NO -

Repair an open in the wire between the HandsFreeLink control unit and the navigation unit.