DTC Troubleshooting: B1776 - With NAV.
DTC B1776:
 Microphone Input/Output Short to Ground/Open (with navigation system)
  1. Connect the HDS to the DLC.
  1. Clear the DTCs with the HDS.
  1. Turn the ignition switch to LOCK (0) and then back to ON (II).
  1. 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.■
  1. Turn the ignition switch to LOCK (0).
  1. Disconnect the 7P connector from the HFT/navigation microphone and the 28P connector from the Hands Free Telephone control unit.
  1. Check for continuity between body ground and terminals No. 13 and No. 14 of the Hands Free Telephone control unit 28P connector individually, then between terminals No. 12 and No. 13.
Is there continuity?
YES -
Replace the faulty harness between the Hands Free Telephone control unit and the HFT/navigation microphone.■
NO -
Go to Step 9 .
  1. Check for continuity between the terminals shown of the Hands Free Telephone control unit 28P connector and the HFT/navigation microphone 7P connector.
Is there continuity?
YES -
Go to Step 10 .
NO -
Replace the faulty harness between the Hands Free Telephone control unit and the HFT/navigation microphone.■
  1. Disconnect navigation unit connector C (16P).
  1. Check for continuity between Hands Free Telephone control unit 28P connector terminals No. 27 and No. 28 and body ground.
Is there continuity?
YES -
Replace the faulty harness between the Hands Free Telephone control unit and the navigation unit.■
NO -
Go to Step 12 .
  1. Check for continuity between the terminals shown of the Hands Free Telephone control unit 28P connector and the navigation unit connector C (16P).
Is there continuity?
YES -
Substitute a known-good Hands Free Telephone control unit, then recheck. If the symptom goes away, replace the original Hands Free Telephone control unit. If the symptom does not go away, replace the faulty navigation unit.■
NO -
Replace the faulty harness between the Hands Free Telephone control unit and the navigation unit.■