DTC Troubleshooting: B1775
DTC B1775: Microphone Input/Output Shorted to Power or Open
NOTE:
1.
Problem verification:

Problem verification
?1.
Check for HFL DTCs.

Is DTC B1775 indicated?

     
YES
     
     
     
The failure is duplicated, go to step 2.
     
NO
     
     
     
Intermittent failure, the system is OK at this time.?
2.
Shorted wire check (MIC+L line to power):

Shorted wire check (MIC+L line to power)
?1.
Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

?2.
Disconnect the following connectors.

?3.
Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.

?4.
Measure the voltage between test points 1 and 2.
Test condition
IG ON (II) or ON mode
 
HandsFreeLink control unit connector A (32P): disconnected
 
Front HFL-navigation-ANC/active sound control microphone 8P connector: disconnected
Test circuit
MIC+L
Test point 1
HandsFreeLink control unit connector A (32P) No. 2 (LT 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+L wire is not shorted to power. Go to step 3.
3.
Open wire check (MIC+L line, MIC+ line):

Open wire check (MIC+L line, MIC+ line)
?1.
Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

?2.
Check for continuity between test points 1 and 2.
Test condition
IG LOCK (0) or OFF mode
 
HandsFreeLink control unit connector A (32P) : disconnected
 
Front HFL-navigation-ANC/active sound control microphone 8P connector: disconnected
Test circuit
MIC+L
Test point 1
HandsFreeLink control unit connector A (32P) No. 2 (LT GRN)
Test point 2
Front HFL-navigation-ANC/active sound control microphone 8P connector No. 2 (LT GRN)

Test circuit
MIC+
Test point 1
HandsFreeLink control unit connector A (32P) No. 1 (PNK)
Test point 2
Front HFL-navigation-ANC/active sound control microphone 8P connector No. 1 (PNK)


Is there continuity?

     
YES: With navigation
     
     
     
The MIC+L and the MIC+ wires are OK. Go to step 5.
     
YES: Without navigation
     
     
     
The MIC+L 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.?
4.
Front HFL-ANC/active sound control microphone check (substitution):

Front HFL-ANC/active sound control microphone check (substitution)
?1.
Substitute a known-good front HFL-ANC/active sound control microphone.

?2.
Reconnect all the connectors.

?3.
Check for HFL DTCs.

Is DTC B1775 indicated?

     
YES
     
     
     
     
NO
     
     
     
Replace the original front HFL-ANC/active sound control microphone.?
5.
Shorted wire check (HFT-NAVI MIC+ line to power):

Shorted wire check (HFT-NAVI MIC+ line to power)
?1.
Disconnect the following connector.

?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 connector A (32P) : disconnected
 
Front HFL-navigation-ANC/active sound control microphone 8P connector: disconnected
 
Audio-navigation unit connector F (18P): disconnected
Test circuit
HFT-NAVI MIC+
Test point 1
HandsFreeLink control unit connector A (32P) No. 18 (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 audio-navigation unit. Replace the affected shielded harness.?
     
NO
     
     
     
The HFT-NAVI MIC+ wire is not shorted to power. Go to step 6.
6.
Determine possible failure area (audio-navigation unit, others):

Determine possible failure area (audio-navigation unit, others)
?1.
Press the engine start/stop button to select the OFF mode.

?2.
Reconnect the HandsFreeLink control unit connector A (32P) and the front HFL-navigation-ANC/active sound control microphone 8P connector.

?3.
Check for HFL DTCs.

Is DTC B1775 indicated?

     
YES
     
     
     
Go to step 7.
     
NO
     
     
     
7.
Front HFL-navigation-ANC/active sound control microphone check (substitution):

Front HFL-navigation-ANC/active sound control microphone check (substitution)
?1.
Press the engine start/stop button to select the OFF mode.

?2.
Substitute a known-good front HFL-navigation-ANC/active sound control microphone.

?3.
Check for HFL DTCs.

Is DTC B1775 indicated?

     
YES
     
     
     
     
NO
     
     
     
Replace the original front HFL-navigation-ANC/active sound control microphone.?