Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
DTC B1775
DTC B1775 : Microphone In/Out Open or Shorted to Power
| DTC Description | DTC |
|---|---|
| B1775 Microphone In/Out Open or Shorted to Power |
DTC (Telematics System)
NOTE: Check the connectors for poor connections or loose terminals.
- Problem verification
-1. Clear the DTCs with the HDS.
-2. Turn the vehicle to the OFF (LOCK) mode and then the ON mode.
-3. Check for DTCs with the HDS.
DTC Description DTC B1775 Microphone In/Out Open or Shorted to Power 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+L line to power)
-1. Turn the vehicle to the OFF (LOCK) mode.
-2. Disconnect the following connectors.
Telematics control unit connector A (36P) Front HFL-navigation-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 Telematics control unit connector A (36P): disconnected Front HFL-navigation-ANC/active sound control microphone 8P connector: disconnected Test circuit MIC+L Test point 1 Front HFL-navigation-ANC/active sound control microphone 8P connector No. 2 (WHT) Test point 2 Body ground Is there about 8.0 V or more?
YES
There is a short to power in the wire between the telematics control unit and the front HFL-navigation-ANC/active sound control microphone. Replace the affected shielded harness.
NO
The MIC+L wire is not shorted to power. Go to step 3.
- Determine possible failure area (MIC+L line, others)
-1. Turn the vehicle to the OFF (LOCK) mode.
-2. Reconnect telematics control unit connector A (36P).
-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-navigation-ANC/active sound control microphone 8P connector: disconnected Test circuit MIC+L Test point 1 Front HFL-navigation-ANC/active sound control microphone 8P connector No. 2 (WHT) Test point 2 Body ground Is there about 8.0 V?
YES
Go to step 5.
NO
Go to step 4.
- Open wire check (MIC+L line)
-1. Turn the vehicle to the OFF (LOCK) mode.
-2. Disconnect the following connector.
Telematics control unit connector A (36P) -3. Check for continuity between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode Front HFL-navigation-ANC/active sound control microphone 8P connector: disconnected Telematics control unit connector A (36P): disconnected Test circuit MIC+L Test point 1 Telematics control unit connector A (36P) No. 4 (WHT) Test point 2 Front HFL-navigation-ANC/active sound control microphone 8P connector No. 2 (WHT) Is there continuity?
YES
Replace the telematics control unit .
NO
There is an open in the wire between the telematics control unit and the front HFL-navigation-ANC/active sound control microphone. Replace the affected shielded harness.
- Open wire check (MIC GND line)
-1. Turn the vehicle to the OFF (LOCK) mode.
-2. Disconnect the following connector.
Telematics control unit connector A (36P) -3. Check for continuity between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode Front HFL-navigation-ANC/active sound control microphone 8P connector: disconnected Telematics control unit connector A (36P): disconnected Test circuit MIC GND Test point 1 Telematics control unit connector A (36P) No. 3 (BLU) Test point 2 Front HFL-navigation-ANC/active sound control microphone 8P connector No. 1 (BLU) Is there continuity?
YES
The MIC GND wire is OK. Go to step 6.
NO
Repair an open in the wire between the telematics control unit and the front HFL-navigation-ANC/active sound control microphone.
- Shorted wire check (HFT-NAVI MIC+ line to power)
-1. Disconnect the following connector.
Audio-navigation unit connector F (18P) -2. Turn the vehicle to the ON mode.
-3. Measure the voltage between test points 1 and 2.
Test condition Vehicle ON mode Front HFL-navigation-ANC/active sound control microphone 8P connector: disconnected Telematics control unit connector A (36P): disconnected Audio-navigation unit connector F (18P): disconnected Test circuit HFT-NAVI MIC+ Test point 1 Audio-navigation unit connector F (18P) No. 13 (RED) Test point 2 Body ground Is there about 8.0 V or more?
YES
There is a short to power in the wire between the telematics 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 7.
- Determine possible failure area (audio-navigation unit, others)
-1. Turn the vehicle to the OFF (LOCK) mode.
-2. Reconnect telematics control unit connector A (36P) and the front HFL-navigation-ANC/active sound control microphone 8P connector .
-3. Clear the DTCs with the HDS.
-4. Turn the vehicle to the OFF (LOCK) mode and then the ON mode.
-5. Check for DTCs with the HDS.
DTC Description DTC B1775 Microphone In/Out Open or Shorted to Power Is DTC B1775 indicated?
YES
Go to step 8.
NO
- Front HFL-navigation-ANC/active sound control microphone check (substitution)
-1. Turn the vehicle to the OFF (LOCK) mode.
-2. Substitute a known-good front HFL-navigation-ANC/active sound control microphone .
-3. Clear the DTCs with the HDS.
-4. Turn the vehicle to the OFF (LOCK) mode and then the ON mode.
-5. Check for DTCs with the HDS.
DTC Description DTC B1775 Microphone Input/Output open or shorted to power Is DTC B1775 indicated?
YES
Replace the telematics control unit .
NO
Replace the original front HFL-navigation-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.