DTC Troubleshooting: B12F0
DTC B12F0: Power Control Unit (Body Control Module) Lost Communication with Electric Steering Lock
NOTE:
If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A.
Before troubleshooting, make sure the No. B8 (15 A) and No. B30 (10 A) fuses in the under-dash fuse/relay box are OK.

DTC Description
DTC
B12F0 Power Control Unit (Body Control Module) Lost Communication with Electric Steering Lock
  

1.
Problem verification 1:

Problem verification 1
?1.
Clear the DTCs with the HDS.


?2.
Do this procedure 10 times: Press the engine start/stop switch to select the OFF (LOCK), ACCESSORY, ON, and OFF (LOCK) mode.

?3.
Check for DTCs with the HDS.
DTC Description
DTC
B12F0 Power Control Unit (Body Control Module) Lost Communication with Electric Steering Lock
  

Is DTC B12F0 indicated?

     
YES
     
     
     
Go to step 2.
     
NO
     
     
     
Intermittent failure, the system is OK at this time. Check for loose or poor connections.?
2.
Open wire check (+B SMART line):

Open wire check (+B SMART line)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the following connector.
Electric steering lock 12P connector

?3.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
Electric steering lock 12P connector: disconnected
Test point 1
Electric steering lock 12P connector No. 3
Test point 2
Body ground


Is there battery voltage?

     
YES
     
     
     
The +B SMART wire is OK. Go to step 3.
     
NO
     
     
     
Repair an open or high resistance in the wire.?
3.
Open wire check (GND line):

Open wire check (GND line)
?1.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
Electric steering lock 12P connector: disconnected
Test point 1
Electric steering lock 12P connector No. 7
Test point 2
Body ground


Is there continuity?

     
YES
     
     
     
The GND wire is OK. Go to step 4.
     
NO
     
     
     
Repair an open or high resistance in the ground wire or poor ground (G503).?
4.
Shorted wire check (IGN TRX line):

Shorted wire check (IGN TRX line)
?1.
Disconnect the following connector.
Body control module connector G (32P)

?2.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
Electric steering lock 12P connector: disconnected
Body control module connector G (32P): disconnected
Test point 1
Electric steering lock 12P connector No. 6
Test point 2
Body ground


Is there continuity?

     
YES
     
     
     
Repair a short to ground in the wire.?
     
NO
     
     
     
The IGN TRX wire is not shorted. Go to step 5.
5.
Open wire check (IGN TRX line):

Open wire check (IGN TRX line)
?1.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
Electric steering lock 12P connector: disconnected
Body control module connector G (32P): disconnected
Test point 1
Electric steering lock 12P connector No. 6
Test point 2
Body control module connector G (32P) No. 28


Is there continuity?

     
YES
     
     
     
The IGN TRX wire is OK. Go to step 6.
     
NO
     
     
     
Repair an open or high resistance in the wire.?
6.
Keyless access system check:

Keyless access system check
?1.
Reconnect these items:
Electric steering lock 12P connector
Body control module connector G (32P)

?2.
With driver's power window open, turn the vehicle to the OFF (LOCK) mode.

?3.
Do the 12 volt battery terminal disconnection procedure.

?4.
Wait for at least 10 seconds to clear the DTCs.

?5.
Do the 12 volt battery terminal reconnection procedure.

?6.
Turn the vehicle to the ON mode then the OFF mode.

?7.
Remove all the keyless remotes from inside the vehicle. Hold them outside the open driver's window, at least 8.0 in (20 cm) away from the vehicle.

?8.
Close all doors, then press the engine start/stop button.

?9.
The keyless remotes bring to the vehicle inside, during close all doors.

?10.
Touch the engine start/stop switch with the keyless remote. The buttons on the keyless remote should be facing you.

?11.
Press the engine start/stop button, and turn the vehicle to the ON mode.

Does the mode change to ON?

     
YES
     
     
     
Go to step 7.
     
NO
     
     
     
Go to step 8.
7.
Problem verification 2:

Problem verification 2
?1.
Clear the DTCs with the HDS.


?2.
Do this procedure 10 times: Press the engine start/stop switch to select the OFF (LOCK), ACCESSORY, ON, and OFF (LOCK) mode.

?3.
Check for DTCs with the HDS.
DTC Description
DTC
B12F0 Power Control Unit Lost Communication with Electric Steering Lock
  

Is DTC B12F0 indicated?

     
YES
     
     
     
     
NO
     
     
     
Intermittent failure, the system is OK at this time. Check for loose or poor connections.?
8.
Electric steering lock communication status check:

Electric steering lock communication status check
?1.
Select COMMUNICATION STATUS in the INSPECTION MENU with the HDS.

?2.
Check the value of STATUS with ELECTRICAL STEERING LOCK, STATUS with KEYLESS ACCESS CONTROL UNIT, and STATUS with BACKUP CONTROL UNIT with the HDS.
 
HDS Description
Value
Status with ESL
MTR CUT1 (Cont) Status
1
MTR CUT2 (IG) Status
1
IG1 Input State of ESL
1
MTRCONT Status of ESL
1
ESL Motor Status
1
Switch D detection for Unlock Status
1
Switch C detection for Unlock Status
1
Switch B detection for Unlock Status
1
Status with KEYLESS ACCESS CONTROL UNIT
FOB KEY Authentication Result
1
Status with BACKUP CONTROL UNIT
FOB KEY Authentication Result
1

NOTE: The parameters are displayed only when the vehicle cannot be turned to the ON mode.

Are only Status with ELECTRICAL STEERING LOCK 1 values indicated?

     
YES
     
     
     
     
NO