HandsFreeLink System Symptom Troubleshooting - HFL does not work properly
HFL does not work properly
NOTE:
Check the vehicle 12 volt battery condition first.
You must be able to duplicate the customer's concern to successfully diagnose the problem. If you cannot duplicate the issue, have the customer demonstrate it.
Check the connectors for poor connections or loose terminals.
1.
HFL switch input check:

HFL switch input check
?1.
Turn the vehicle to the ON mode.

?2.
Go into the System Diagnostic Mode, and use the Hard Key to check the HFL switch (PICK-UP button, HANG-UP/BACK button, TALK button).

Does all the HFL switch buttons respond?

     
YES
     
     
     
Go to step 2.
     
NO
     
     
     
2.
Bluetooth module check:

Bluetooth module check
?1.
Go into the System Diagnostic Mode, and use the HFT/Mic to check the Bluetooth Connection Diagnosis.

Does the status indicate OK?

     
YES
     
     
     
Go to step 3.
     
NO
     
     
     
3.
Microphone input check:

Microphone input check
?1.
Go into the System Diagnostic Mode, and use the HFT/Mic to check the microphone.

?2.
Press the TALK button, then say ‘‘testing’’ in front of the microphone to check the Mic level.

Is the microphone level OK?

     
YES
     
     
     
Go to step 4.
     
NO
     
     
     
Go to step 6.
4.
Cell phone connection check (known-good phone):

Cell phone connection check (known-good phone)
?1.
Turn the vehicle to the OFF (LOCK) mode then the ON mode.

?2.
Pair a known-good cell phone with Bluetooth to the customer's vehicle.

Can you pair the cell phone?

     
YES: USA models
     
     
     
     
YES: Except USA models
     
     
     
Go to step 5.
     
NO
     
     
     
5.
Cell phone connection check (customer's phone):

Cell phone connection check (customer's phone)
?1.
Pair the customer's cell phone with Bluetooth to the customer's vehicle.

Can you pair the cell phone, and does it operate normally?

     
YES
     
     
     
The HFL system is OK at this time. Inquire if there are any known issues for the problem.?
     
NO
     
     
     
The customer's cell phone is defective or not compatible.?
6.
Determine possible failure area (microphone signal circuit, others):

Determine possible failure area (microphone signal circuit, others)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the following connector.
HFL 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
 
HFL microphone 8P connector: disconnected
Test point 1
HFL microphone 8P connector No. 1
Test point 2
HFL microphone 8P connector No. 2

Is there about 8.0 V?

     
YES
     
     
     
Go to step 7.
     
NO
     
     
     
Go to step 10.
7.
Determine possible failure area (MIC PWR line, others):

Determine possible failure area (MIC PWR line, others)
?1.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle ON mode
 
HFL microphone 8P connector: disconnected
Test point 1
HFL microphone 8P connector No. 4
Test point 2
Body ground

Is there about 8.0 V?

     
YES
     
     
     
     
NO
     
     
     
Go to step 8.
8.
Open wire check (MIC PWR line):

Open wire check (MIC PWR line)
?1.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle ON mode
 
HFL microphone 8P connector: disconnected
Test point 1
Audio unit connector C (32P) No. 7
Test point 2
Body ground

Is there about 8.0 V?

     
YES
     
     
     
Repair an open in the wire between the HFL microphone and the audio unit.?
     
NO
     
     
     
The MIC PWR wire is not open. Go to step 9.
9.
Shorted wire check (MIC PWR line):

Shorted wire check (MIC PWR line)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the following connector.
Audio unit connector C (32P)

?3.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
HFL microphone 8P connector: disconnected
 
Audio unit connector C (32P): disconnected
Test point 1
Audio unit connector C (32P) No. 7
Test point 2
Body ground

Is there continuity?

     
YES
     
     
     
There is a short to body ground in the wire between the HFL microphone and the audio unit. Replace the affected shielded harness.?
     
NO
     
     
     
10.
Determine possible failure area (MIC? line, others):

Determine possible failure area (MIC? line, others)
?1.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle ON mode
 
HFL microphone 8P connector: disconnected
Test point 1
HFL microphone 8P connector No. 2
Test point 2
Body ground

Is there about 8.0 V?

     
YES
     
     
     
Repair an open in the wire between the HFL microphone and the audio unit.?
     
NO
     
     
     
Go to step 11.
11.
Open wire check (MIC+ line):

Open wire check (MIC+ line)
?1.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle ON mode
 
HFL microphone 8P connector: disconnected
Test point 1
Audio unit connector C (32P) No. 22
Test point 2
Body ground

Is there about 8.0 V?

     
YES
     
     
     
Repair an open in the wire between the HFL microphone and the audio unit.?
     
NO
     
     
     
The MIC+ wire is not open. Go to step 12.
12.
Shorted wire check (MIC+ line):

Shorted wire check (MIC+ line)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the following connector.
Audio unit connector C (32P)

?3.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
HFL microphone 8P connector: disconnected
 
Audio unit connector C (32P): disconnected
Test point 1
Audio unit connector C (32P) No. 22
Test point 2
Body ground

Is there continuity?

     
YES
     
     
     
There is a short to body ground in the wire between the HFL microphone and the audio unit. Replace the affected shielded harness.?
     
NO
     
     
     
The MIC+ wire is not shorted to ground. Go to step 13.
13.
Shorted wire check (MIC+ line to MIC? line, SH MIC line):

Shorted wire check (MIC+ line to MIC? line, SH MIC line)
?1.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
HFL microphone 8P connector: disconnected
 
Audio unit connector C (32P): disconnected
Test point 1
Audio unit connector C (32P) No. 6
Test point 2
Audio unit connector C (32P) No. 22


Is there continuity?

     
YES
     
     
     
There is a short in the wires between the HFL microphone and the audio unit. Replace the affected shielded harness.?
     
NO