DTC B1776: Microphone Input/Output Short to Ground (with navigation)

WARNING: This page is about a different car, the 2011 Acura TL, 2010 Acura TL, and 2009 Acura TL. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN system diagnosis test mode A (see TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A )

Connect the HDS to the DLC (see GENERAL TROUBLESHOOTING INFORMATION )
Clear the DTCs with the HDS
Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode, then back to ON (II), or the ON mode
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
Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
Disconnect the HFL-navigation microphone 7P connector
Remove the center console panel (see CENTER CONSOLE PANEL REMOVAL/INSTALLATION )
Disconnect the HandsFreeLink control unit 28P connector (see step 2) under HANDSFREELINK CONTROL UNIT REMOVAL/INSTALLATION)
Check for continuity between body ground and terminals No 13 and No 14 of the HandsFreeLink control unit 28P connector individually, then between terminals No 12 and No 13

Fig 1: Checking Continuity Between Handsfreelink Control Unit 28P Connector Terminals No 12 And No 13 And Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -There is a short in the wires between the HandsFreeLink control unit and the HFL-navigation microphone Replace the affected shielded harness

NO -Go to step 10
Check for continuity between the terminals shown of the HandsFreeLink control unit 28P connector terminals No. 13 and No. 14 and HFL-navigation microphone 7P connector terminals No. 3 and No. 2 respectively

Fig 2: Checking Continuity Between Handsfreelink Control Unit 28P Connector And Hfl-Navigation Microphone 7P Connector
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Go to step 11

NO -There is an open in the wire between the HandsFreeLink control unit and the HFL-navigation microphone Replace the affected shielded harness
Disconnect audio-navigation unit connector H (28P)
Check for continuity between HandsFreeLink control unit 28P connector terminals No 27 and No 28 and body ground individually

Fig 3: Checking Continuity Between Handsfreelink Control Unit 28P Connector Terminals No 27 And No 28 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -There is a short to body ground in the wires between the HandsFreeLink control unit and the audio-navigation unit Replace the affected shielded harness

NO -Go to step 13
Check for continuity between HandsFreeLink control unit 28P connector terminals No. 27 and No. 28 and audio-navigation unit connector H (28P) terminals No. 28 and No. 27 respectively

Fig 4: Checking Continuity Between Handsfreelink Control Unit 28P Connector And Audio-Navigation Unit Connector H (28P)
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Substitute a known-good HandsFreeLink control unit (see HFL SWITCH TEST ), and recheck If the symptom goes away, replace the original HandsFreeLink control unit If the symptom does not go away, replace the faulty audio-navigation unit (see AUDIO-NAVIGATION UNIT REMOVAL/INSTALLATION )

NO -There is an open in the wires between the HandsFreeLink control unit and the audio-navigation unit Replace the affected shielded harness