DTC B1775: Microphone input/output shorted to power (without navigation)

WARNING: This page is about a different car, the 2013 Acura MDX, 2012 Acura MDX, 2011 Acura MDX, and 2010 Acura MDX. 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 HOW TO CHECK FOR DTCS WITH THE HDS ).
Clear the DTCs with the HDS.
Turn the ignition switch to LOCK (0), and then back to ON (II).
Check for DTCs with the HDS.
Is DTC B1775 indicated?

YES -Go to step 5.

NO -Intermittent failure, the system is OK at this time.
Turn the ignition switch to LOCK (0).
Disconnect the roof console 20P connector.
Disconnect the HandsFreeLink control unit 28P connector (see step 2 under HANDSFREELINK CONTROL UNIT REMOVAL/INSTALLATION ).
Turn the ignition switch to ON (II).
Measure the voltage between HandsFreeLink control unit 28P connector terminal No. 13 and body ground.

Fig 1: Measuring Voltage Between Handsfreelink Control Unit 28P Connector Terminal No. 13 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there battery voltage?

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

NO -Go to step 10.
Turn the ignition switch to LOCK (0).
Check for continuity between HandsFreeLink control unit 28P connector terminal No. 13 and roof console 20P connector terminal No. 20.

Fig 2: Checking Continuity Between Handsfreelink Control Unit 28P Connector And Roof Console 20P Connector
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

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

NO -There is an open in the wire between the HandsFreeLink control unit and the HFL microphone. Replace the affected shielded harness.