DTC B1776: Microphone Input/Output Shorted to Ground

WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2017 Honda Odyssey, 2016 Honda Odyssey, 2015 Honda Odyssey, 2014 Honda Odyssey, and 2013 Honda Odyssey. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Check the vehicle battery condition first (see BATTERY TEST ).

Do the HFL Self-Diagnostic Function (see SELF-DIAGNOSTIC FUNCTION ), and check for HFL DTCs.
Is DTC B1776 indicated?

YES -Go to step 2.

NO -Intermittent failure, the system is OK at this time.
Turn the ignition switch to LOCK (0).
Disconnect the front HFL-navigation-ANC microphone 7P connector.
Disconnect the HandsFreeLink control unit 32P connector.
Check for continuity between HandsFreeLink control unit 32P connector terminal No. 2 and body ground, then between terminals No. 2 and No. 3.

Fig 1: Checking For Continuity Between HandsFreeLink Control Unit 32P Connector Terminal No. 2 And Body Ground, Then Between Terminals No. 2 And No. 3
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

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

NO -Go to step 6.
Disconnect audio-navigation unit connector C (28P).
Check for continuity between HandsFreeLink control unit 32P connector terminal No. 18 and body ground.

Fig 2: Checking Continuity Between Body Ground And HFL Control Unit 32P Connector Terminals 17 And 18
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

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

NO -Go to step 8.
Reconnect the HandsFreeLink control unit 32P connector and the front HFL-navigation-ANC microphone 7P connector.
Check for HFL DTCs (see How to Check the HFL DTC's (with navigation) ).
Is DTC B1776 indicated?

YES -Substitute a known-good front HFL-navigation-ANC microphone (see FRONT HFL-NAVIGATION-ANC MICROPHONE REMOVAL/INSTALLATION ), and recheck. If the symptom/indication goes away, replace the original front HFL-navigation-ANC microphone (see FRONT HFL-NAVIGATION-ANC MICROPHONE REMOVAL/INSTALLATION ). If the symptom/indication is still present, replace the HandsFreeLink control unit (see HANDSFREELINK CONTROL UNIT REMOVAL/INSTALLATION ).

NO -Substitute a known-good audio-navigation unit (including the HDD) (see AUDIO-NAVIGATION UNIT REMOVAL/INSTALLATION ), and recheck. If the symptom/indication goes away, replace the original audio-navigation unit (see AUDIO-NAVIGATION UNIT REMOVAL/INSTALLATION ).