DTC B1775: Microphone Input/Output Shorted to Power or Open

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 B1775 indicated?

YES -Go to step 2.

NO -Intermittent failure, the system is OK at this time.
Turn the ignition switch to LOCK (0).
Remove the front HFL-navigation-ANC microphone (see FRONT HFL-NAVIGATION-ANC MICROPHONE REMOVAL/INSTALLATION ), and check that the front HFL-navigation-ANC microphone 7P connector is properly connected.
Is the connector properly connected?

YES -Go to step 4.

NO -Reconnect the connector, and recheck the function.
Disconnect the front HFL-navigation-ANC microphone 7P connector.
Disconnect the HandsFreeLink control unit 32P connector.
Turn the ignition switch to ON (II).
Measure the voltage between HandsFreeLink control unit 32P connector terminal No. 2 and body ground.

Fig 1: Measuring Voltage Between Handsfreelink Control Unit 32P Connector Terminal 2 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there voltage?

YES -There is a short to power in the wire the HandsFreeLink control unit and the front HFL-navigation-ANC microphone. Replace the affected shielded harness.

NO -Go to step 8.
Turn the ignition switch to LOCK (0).
Check for continuity between HandsFreeLink control unit 32P connector terminals No. 1 and No. 2 and front HFL-navigation-ANC microphone 7P connector terminals No. 6 and No. 5 respectively.

Fig 2: Checking Continuity Between HFL Control Unit 32P Connector Terminal 2 And Front HFL-Navigation-ANC Microphone 7P Connector Terminal 5
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Go to step 10.

NO -There is an open in the wire between the HandsFreeLink control unit and the front HFL-navigation-ANC microphone. Replace the affected shielded harness.
Disconnect audio-navigation unit connector C (28P).
Turn the ignition switch to ON (II).
Measure the voltage between HandsFreeLink control unit 32P connector terminal No. 18 and body ground.

Fig 3: Measuring voltage between HandsFreeLink control unit 32P connector terminal No. 18 and body ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there voltage?

YES -There is a short to power in the wire between the HandsFreeLink control unit and the audio-navigation unit. Replace the affected shielded harness.

NO -Go to step 13.
Turn the ignition switch to LOCK (0).
Reconnect the HandsFreeLink control unit 32P connector and the front HFL-navigation-ANC microphone 7P connector.
Turn the ignition switch to ON (II).
Check for HFL DTCs.
Is DTC B1775 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 ).