DTC B1776: Microphone Input/Output Shorted to Ground (HandsFreeLink Control Unit)
NOTE:
- Check the vehicle 12 volt battery condition first - Refer to: 12 Volt Battery Test (Without SH-AWD) or 12 Volt Battery Test (With SH-AWD) .
- Before you troubleshoot, make sure to follow the General Troubleshooting Information .
- Check the connectors for poor connections or loose terminals.
- Problem verification
-1. Check for HFL DTCs.
Is DTC B1776 indicated?
YES
The failure is duplicated, go to step 2.
NO
Intermittent failure, the system is OK at this time.
- Determine possible failure area (Microphone, others)
-1. Turn the vehicle to the OFF (LOCK) mode.
- 2. Disconnect the following connector.
Front HFL-ANC/active sound control microphone 8P connector - 3. Turn the vehicle to the ON mode.
- 4. Measure the voltage between test points 1 and 2.
Test condition Vehicle ON mode Front HFL-ANC/active sound control microphone 8P connector: disconnected Test point 1 Front HFL-ANC/active sound control microphone 8P connector No. 2 Test point 2 Body ground Is there about 8.0 V?
YES
Replace the front HFL-ANC/active sound control microphone .
NO
Go to step 3.
- Shorted wire check (MIC SIG L line)
-1. Turn the vehicle to the OFF (LOCK) mode.
- 2. Disconnect the following connector.
HandsFreeLink control unit connector A (32P) - 3. Check for continuity between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode Front HFL-ANC/active sound control microphone 8P connector: disconnected HandsFreeLink control unit connector A (32P): disconnected Test point 1 HandsFreeLink control unit connector A (32P) No. 2 - Refer to: HandsFreeLink Control Unit Connector For Inputs And Outputs (2015-17) or HandsFreeLink Control Unit Connector for Inputs and Outputs (2018-19) Test point 2 Body ground Is there continuity?
YES
There is a short to body ground in the wire between the HandsFreeLink control unit and the front HFL-ANC/active sound control microphone. Replace the affected shielded harness.
NO
The MIC SIG L wire is not shorted to ground. Go to step 4.
- Shorted wire check (MIC SIG L line to another lines)
-1. Check for continuity between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode Front HFL-ANC/active sound control microphone 8P connector: disconnected HandsFreeLink control unit connector A (32P): disconnected Test point 1 HandsFreeLink control unit connector A (32P) No. 2 - Refer to: HandsFreeLink Control Unit Connector For Inputs And Outputs (2015-17) or HandsFreeLink Control Unit Connector for Inputs and Outputs (2018-19) Test point 2 HandsFreeLink control unit connector A (32P) No. 1 - Refer to: HandsFreeLink Control Unit Connector For Inputs And Outputs (2015-17) or HandsFreeLink Control Unit Connector for Inputs and Outputs (2018-19) Test point 1 HandsFreeLink control unit connector A (32P) No. 2 - Refer to: HandsFreeLink Control Unit Connector For Inputs And Outputs (2015-17) or HandsFreeLink Control Unit Connector for Inputs and Outputs (2018-19) Test point 2 HandsFreeLink control unit connector A (32P) No. 3 - Refer to: HandsFreeLink Control Unit Connector For Inputs And Outputs (2015-17) or HandsFreeLink Control Unit Connector for Inputs and Outputs (2018-19) Is there continuity?
YES
There is a short in the wires between the HandsFreeLink control unit and the front HFL-ANC/active sound control microphone. Replace the affected shielded harness.
NO: Without navigation
Replace the HandsFreeLink control unit .
NO: With navigation
The MIC SIG L wire is OK. Go to step 5.
- Shorted wire check (NAVI HFT MIC+ line)
-1. Disconnect the following connector.
Audio-navigation unit connector F (18P) - 2. Check for continuity between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode Front HFL-ANC/active sound control microphone 8P connector: disconnected HandsFreeLink control unit connector A (32P) : disconnected Audio-navigation unit connector F (18P) Test point 1 Audio-navigation unit connector F (18P) No. 13 - Refer to: Audio-Navigation Unit Connector For Inputs And Outputs (With Auto Idle Stop System) (2015-17) or Audio-Navigation Unit Connector for Inputs and Outputs (Without Auto Idle Stop System) (2015-17) or Audio-Navigation Unit Connector for Inputs and Outputs (Undefined) (2018), or Audio-Navigation Unit Connector for Inputs and Outputs (2019) Test point 2 Body ground Is there continuity?
YES
There is a short to body ground in the wire between the HandsFreeLink control unit and the audio-navigation unit. Replace the affected shielded harness.
NO
The NAVI HFT MIC+ wire is not shorted to ground. Go to step 6.
- Shorted wire check (NAVI HFT MIC+ line to another lines)
-1. Check for continuity between test points 1 and 2.
Test point 1 Audio-navigation unit connector F (18P) No. 13 - Refer to: Audio-Navigation Unit Connector For Inputs And Outputs (With Auto Idle Stop System) (2015-17) or Audio-Navigation Unit Connector for Inputs and Outputs (Without Auto Idle Stop System) (2015-17) or Audio-Navigation Unit Connector for Inputs and Outputs (Undefined) (2018), or Audio-Navigation Unit Connector for Inputs and Outputs (2019) Test point 2 Audio-navigation unit connector F (18P) No. 6 - Refer to: Audio-Navigation Unit Connector For Inputs And Outputs (With Auto Idle Stop System) (2015-17) or Audio-Navigation Unit Connector for Inputs and Outputs (Without Auto Idle Stop System) (2015-17) or Audio-Navigation Unit Connector for Inputs and Outputs (Undefined) (2018), or Audio-Navigation Unit Connector for Inputs and Outputs (2019) Is there continuity?
YES
There is a short in the wires between the HandsFreeLink control unit and the audio-navigation unit. Replace the affected shielded harness.
NO
The NAVI HFT MIC+ wire is OK. Go to step 7.
- HandsFreeLink control unit check
-1. Reconnect HandsFreeLink control unit connector A (32P).
- 2. Reconnect the front HFL-ANC/active sound control microphone 8P connector.
- 3. Check for HFL DTCs.
Is DTC B1776 indicated?
YES
Replace the HandsFreeLink control unit .
NO