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DTC B1775: Microphone Input/Output Shorted to Power or Open (2013-18)
- Check the vehicle battery condition first .
- Before you troubleshoot, make sure to follow the General Troubleshooting Information - Refer to: How to Troubleshoot the HandsFreeLink System (2013-18), or How to Troubleshoot the HandsFreeLink System(With navigation) (2016-18) .
- Check the connectors for poor connections or loose terminals.
- Problem verification:
Check for HFL DTCs - Refer to: How to Troubleshoot the HandsFreeLink System (2013-18), or How to Troubleshoot the HandsFreeLink System(With navigation) (2016-18) .
Is DTC B1775 indicated?
YES
The failure is duplicated, go to step 2.
NO
Intermittent failure, the system is OK at this time.
- Shorted wire check (MIC+ line to power):
Press the engine start/stop button to select the OFF mode.
- 2. Disconnect the following connectors.
HandsFreeLink control unit 32P connector Front HFL-ANC/active sound control microphone 8P connector - 3. Press the engine start/stop button to select the ON mode.
- 4. Measure the voltage between test points 1 and 2.
Test condition ON mode HandsFreeLink control unit 32P connector: disconnected Front HFL-ANC/active sound control microphone 8P connector: disconnected Test circuit MIC+ Test point 1 HandsFreeLink control unit 32P connector No. 2 (GRN) Test point 2 Body ground Is there any voltage?
YES
There is a short to power 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+ wire is not shorted to power. Go to step 3.
- Open wire check (MIC + line, MIC - line):
Press the engine start/stop button to select the OFF mode.
- 2. Check for continuity between test points 1 and 2.
Test condition OFF mode HandsFreeLink control unit 32P connector: disconnected Front HFL-ANC/active sound control microphone 8P connector: disconnected Test circuit MIC + Test point 1 HandsFreeLink control unit 32P connector No. 2 (GRN) Test point 2 Front HFL-ANC/active sound control microphone 8P connector No. 2 (GRN) Test circuit MIC - Test point 1 HandsFreeLink control unit 32P connector No. 1 (RED) Test point 2 Front HFL-ANC/active sound control microphone 8P connector No. 3 (RED) Is there continuity?
YES: With navigation
The MIC + and the MIC - wires are OK. Go to step 5.
YES: Without navigation
The MIC + and the MIC - wires are OK. Go to step 4.
NO
There is an open in the wire(s) between the HandsFreeLink control unit and the front HFL-ANC/active sound control microphone. Replace the affected shielded harness.
- HandsFreeLink control unit check:
Substitute a known-good front HFL-ANC/active sound control microphone .
- 2. Reconnect all the connectors.
- 3. Check for HFL DTCs - Refer to: How to Troubleshoot the HandsFreeLink System (2013-18), or How to Troubleshoot the HandsFreeLink System(With navigation) (2016-18) .
Is DTC B1775 indicated?
YES
Replace the HandsFreeLink control unit .
NO
Replace the original front HFL-ANC/active sound control microphone.
- Shorted wire check (HFT-NAVI MIC+ line to power):
Disconnect the following connector.
Audio-navigation unit connector H (28P) - Refer to: Audio-Navigation Unit Removal and Installation (2013-15), or Audio-Navigation Unit Removal and Installation (2016-18) - 2. Press the engine start/stop button to select the ON mode.
- 3. Measure the voltage between test points 1 and 2.
Test condition ON mode HandsFreeLink control unit 32P connector: disconnected Front HFL-ANC/active sound control microphone 8P connector: disconnected Audio-navigation unit connector H (28P): disconnected Test circuit HFT-NAVI MIC+ Test point 1 HandsFreeLink control unit 32P connector No. 18 (BLU) Test point 2 Body ground Is there any 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
The HFT-NAVI MIC+ wire is not shorted to power. Go to step 6.
- Determine possible failure area (audio-navigation unit, others):
Press the engine start/stop button to select the OFF mode.
- 2. Reconnect the HandsFreeLink control unit 32P connector and the front HFL-ANC/active sound control microphone 8P connector .
- 3. Check for HFL DTCs - Refer to: How to Troubleshoot the HandsFreeLink System (2013-18), or How to Troubleshoot the HandsFreeLink System(With navigation) (2016-18) .
Is DTC B1775 indicated?
YES
Go to step 7.
NO
Replace the audio-navigation unit - Refer to: Audio-Navigation Unit Removal and Installation (2013-15), or Audio-Navigation Unit Removal and Installation (2016-18) .
- HandsFreeLink control unit check:
Press the engine start/stop button to select the OFF mode.
- 2. Substitute a known-good front HFL-ANC/active sound control microphone .
- 3. Check for HFL DTCs - Refer to: How to Troubleshoot the HandsFreeLink System (2013-18), or How to Troubleshoot the HandsFreeLink System(With navigation) (2016-18) .
Is DTC B1775 indicated?
YES
Replace the HandsFreeLink control unit .
NO
Replace the original front HFL-ANC/active sound control microphone.
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.