HandsFreeLink System Symptom Troubleshooting - HFL does not respond
HFL does not respond

1.
Problem verification 1:

Problem verification 1
?1.
Turn the vehicle to the ON mode.

?2.
Press the PHONE button, and check if the multi-information display unit changes to the HFL information screen.

Is the HFL information displayed?

     
YES
     
     
     
Go to step 2.
     
NO: With short message service
     
     
     
The failure is duplicated, go to step 3.
     
NO: Without short message service
     
     
     
Go to step 11.
2.
Problem verification 2:

Problem verification 2
?1.

Is HFL prompt played?

     
YES: ‘‘The HFT is OK.’’ is played
     
     
     
Intermittent failure, the system is OK at this time. If possible, have the customer demonstrate the issue.?
     
YES: ‘‘The HFT is NG.’’ is played
     
     
     
     
NO
     
     
     
3.
Determine possible failure area (GA +B line, others):

Determine possible failure area (GA +B line, others)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle OFF mode
Test point 1
Test point 2
Body ground

Is there battery voltage?

     
YES
     
     
     
The GA +B wire is OK. Go to step 6.
     
NO
     
     
     
Go to step 4.
4.
Open wire check (GA +B line):

Open wire check (GA +B line)
?1.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
Test point 1
Test point 2
Body ground

Is there battery voltage?

     
YES
     
     
     
Repair an open in the wire between the audio unit and the HandsFreeLink control unit.?
     
NO
     
     
     
The GA +B wire is not open. Go to step 5.
5.
Shorted wire check (GA +B line):

Shorted wire check (GA +B line)
?1.
Disconnect the following connectors.
Audio unit connector C (14P)
HandsFreeLink control unit 32P connector

?2.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
HandsFreeLink control unit 32P connector: disconnected
 
Audio unit connector C (14P): disconnected
   
Test point 1
Test point 2
Body ground

Is there continuity?

     
YES
     
     
     
Repair a short to body ground in the wire between the audio unit and the HandsFreeLink control unit.?
     
NO
     
     
     
6.
Determine possible failure area (GA GND line, others):

Determine possible failure area (GA GND line, others)
?1.
Turn the vehicle to the ON mode.

?2.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle ON mode
Test point 1
Test point 2
Body ground

Is there less than 0.2 V?

     
YES
     
     
     
The GA GND wire is OK. Go to step 8.
     
NO
     
     
     
Go to step 7.
7.
Open wire check (GA GND line):

Open wire check (GA GND line)
?1.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle ON mode
Test point 1
Test point 2
Body ground

Is there any voltage?

     
YES
     
     
     
     
NO
     
     
     
Repair an open or high resistance in the wire between the audio unit and the HandsFreeLink control unit.?
8.
Determine possible failure area (GA SYS ON line, others):

Determine possible failure area (GA SYS ON line, others)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
Test point 1
Test point 2
Body ground

Is there battery voltage?

     
YES
     
     
     
The GA SYS ON wire is OK. Go to step 10.
     
NO
     
     
     
Go to step 9.
9.
Open wire check (GA SYS ON line):

Open wire check (GA SYS ON line)
?1.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
Test point 1
Test point 2
Body ground

Is there battery voltage?

     
YES
     
     
     
Repair an open in the wire between the audio unit and the HandsFreeLink control unit.?
     
NO
     
     
     
10.
Audio unit check:

Audio unit check
?1.
Turn the vehicle to the ON mode.

?2.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle ON mode
Test point 1
Test point 2
Body ground

Is there less than 0.2 V?

     
YES
     
     
     
Go to step 14.
     
NO
     
     
     
11.
Fuse check:

Fuse check
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Check the following fuse.
Fuse
No. B19 (7.5 A)
Location
Under-dash fuse/relay box

Fuse
No. B25 (10 A)
Location
Under-dash fuse/relay box

Is the fuse OK?

     
YES
     
     
     
Go to step 12.
     
NO
     
     
     
Replace the fuse(s), and recheck. If the fuse(s) blows again, check for a short in the No. B19 (7.5 A) fuse and/or the No. B25 (10 A) fuse circuit(s).?
12.
Open wire check (+B AUDIO line, ACC line):

Open wire check (+B AUDIO line, ACC line)
?1.
Turn the vehicle to the ON mode.

?2.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle ON mode
Test point 1
Test point 2
Body ground

Test point 1
Test point 2
Body ground

Is there battery voltage?

     
YES
     
     
     
The +B AUDIO and the ACC wires are OK. Go to step 13.
     
NO
     
     
     
Repair an open in the wire between the No. B19 (7.5 A) fuse in the under-dash fuse/relay box and/or the No. B25 (10 A) fuse in the under-dash fuse/relay box and the HandsFreeLink control unit.?
13.
Open wire check (GND line):

Open wire check (GND line)
?1.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle ON mode
Test point 1
Test point 2
Body ground

Is there less than 0.2 V?

     
YES
     
     
     
The GND wire is OK. Go to step 14.
     
NO
     
     
     
Repair an open in the wire between the HandsFreeLink control unit and body ground (G503).?
14.
Shorted wire check (GA BUS+ line, GA BUS? line):

Shorted wire check (GA BUS+ line, GA BUS? line)
?1.
Disconnect the following connectors.
Audio unit connector C (14P)
HandsFreeLink control unit 32P connector
Multi-information display unit connector A (32P)

?2.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
Audio unit connector C (14P): disconnected
 
HandsFreeLink control unit 32P connector: disconnected
 
Multi-information display unit connector A (32P): disconnected
Test point 1
Test point 2
Body ground

Test point 1
Test point 2
Body ground

Is there continuity?

     
YES
     
     
     
There is a short to body ground in the GA BUS wire(s). Replace the affected shielded harness.?
     
NO
     
     
     
The GA BUS+ and the GA BUS? wires are not shorted to ground. Go to step 15.
15.
Shorted wire check (GA BUS+ line to GA BUS? line):

Shorted wire check (GA BUS+ line to GA BUS? line)
?1.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
Audio unit connector C (14P): disconnected
 
HandsFreeLink control unit 32P connector: disconnected
 
Multi-information display unit connector A (32P): disconnected
Test point 1
Test point 2

Is there continuity?

     
YES
     
     
     
There is a short in the GA BUS wires. Replace the affected shielded harness.?
     
NO
     
     
     
The GA BUS+ and the GA BUS? wires are not shorted. Go to step 16.
16.
Shorted wire check (SH GA BUS line to another lines):

Shorted wire check (SH GA BUS line to another lines)
?1.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
Audio unit connector C (14P): disconnected
 
HandsFreeLink control unit 32P connector: disconnected
 
Multi-information display unit connector A (32P): disconnected
Test point 1
Test point 2


Is there continuity?

     
YES
     
     
     
There is a short in the GA BUS wires. Replace the affected shielded harness.?
     
NO
     
     
     
The SH GA BUS wire is OK. Go to step 17.
17.
Open wire check (GA BUS+ line, GA BUS? line):

Open wire check (GA BUS+ line, GA BUS? line)
?1.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
Audio unit connector C (14P): disconnected
 
HandsFreeLink control unit 32P connector: disconnected
 
Multi-information display unit connector A (32P): disconnected
Test point 1
Test point 2


Is there continuity?

     
YES
     
     
     
The GA BUS+ and the GA BUS? wires are OK. Go to step 18.
     
NO
     
     
     
There is an open in the wire(s) between the audio unit and the HandsFreeLink control unit. Replace the affected shielded harness.?
18.
Determine possible failure area (related unit, others):

Determine possible failure area (related unit, others)
?1.
Reconnect the HandsFreeLink control unit 32P connector and audio unit connector C (14P).

?2.
Turn the vehicle to the ON mode.

?3.

Do you hear, ‘‘The HFT is OK’’?

     
YES
     
     
     
     
NO
     
     
     
Go to step 19.
19.
HandsFreeLink control unit check (substitution):

HandsFreeLink control unit check (substitution)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.

?3.
Reconnect all the connectors, and recheck.

Does the symptom go away?

     
YES
     
     
     
     
NO