DTC Troubleshooting: B1779
DTC B1779: HandsFreeLink Steering Wheel Switch Failure
NOTE:
1.
Problem verification:

Problem verification
?1.
Start the engine, and turn the steering wheel left and right several times.

?2.
Check for HFL DTCs.

Is DTC B1779 indicated?

     
YES
     
     
     
The failure is duplicated, go to step 2.
     
NO
     
     
     
Intermittent failure, the system is OK at this time.?
2.
Determine possible failure area (HFL switch, others):

Determine possible failure area (HFL switch, others)
?1.
Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

?2.
Do the HFL Switch Test.

Is the switch OK?

     
YES
     
     
     
Go to step 3.
     
NO
     
     
     
3.
Shorted wire check (HFT/NAVI REMOTE SW line to power):

Shorted wire check (HFT/NAVI REMOTE SW line to power)
?1.
Disconnect the following connector.

?2.
Reconnect cable reel connector C (20P).

?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
 
HFL switch 12P connector: disconnected
Test circuit
HFT/NAVI REMOTE SW
Test point 1
HandsFreeLink control unit connector A (32P) No. 15 (LT BLU)
Test point 2
Body ground


Is there any voltage?

     
YES
     
     
     
Repair a short to power in the wire between the HandsFreeLink control unit and the HFL switch. If the wire is OK, replace the cable reel.?
     
NO
     
     
     
The HFT/NAVI REMOTE SW wire is not shorted to power. Go to step 4.
4.
Open wire check (HFT/NAVI REMOTE SW line):

Open wire check (HFT/NAVI REMOTE SW 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
 
HFL switch 12P connector: disconnected
Test circuit
HFT/NAVI REMOTE SW
Test point 1
HandsFreeLink control unit connector A (32P) No. 15 (LT BLU)
Test point 2
HFL switch 12P connector No. 3 (PUR)


Is there continuity?

     
YES
     
     
     
The HFT/NAVI REMOTE SW wire is OK. Go to step 5.
     
NO
     
     
     
Repair an open in the wire between the HandsFreeLink control unit and the HFL switch. If the wire is OK, replace the cable reel.?
5.
Open wire check (GND line):

Open wire check (GND line)
?1.
Measure the voltage between test points 1 and 2.
Test condition
IG ON (II) or ON mode
 
HandsFreeLink control unit connector A (32P): disconnected
 
HFL switch 12P connector: disconnected
Test circuit
GND
Test point 1
HFL switch 12P connector No. 4 (BLK)
Test point 2
Body ground


Is there less than 0.2 V?

     
YES
     
     
     
     
NO
     
     
     
Repair an open or high resistance in the wire between the HFL switch and body ground (G551).?