DTC Troubleshooting: B1780
DTC B1780: HandsFreeLink Steering Wheel Switch Line Short
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 B1780 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):

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

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

?3.
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
Body ground


Is there continuity?

     
YES
     
     
     
Repair a short to body ground in the wire between the HandsFreeLink control unit and the HFL switch. If the wire is OK, replace the cable reel.?
     
NO