DTC Troubleshooting: U0146
DTC U0146: F-CAN Malfunction (TCM-CAN Gateway)
NOTE:
Before you troubleshoot, review the General Troubleshooting Information.
This code is caused by an electrical circuit problem and cannot be caused by a mechanical problem in the transmission.
According to the detected DTC(s), check for the power circuit of the CAN gateway.

DTC Description
Confirmed DTC
Pending DTC
Freeze Frame
U0146 F-CAN Malfunction (TCM-CAN Gateway)
      

1.
CAN gateway system DTC check:

CAN gateway system DTC check
?1.
Check for CAN gateway system DTCs with the HDS.
DTC Description
DTC
   

Are any DTCs indicated?

     
YES
     
     
     
     
NO
     
     
     
Go to step 2.
2.
F-CAN circuit communication check:

F-CAN circuit communication check
?1.
Select the FUNCTION TEST in the CAN gateway with the HDS, then select the F-CAN Bus Connected Unit Check.

  

Which result is indicated?

     
TCM (Bus A) is Not Available
     
     
     
Go to step 3.
     
TCM is Detected
     
     
     
Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the CAN gateway and the TCM. If the freeze data/on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the freeze data/on-board snapshot.?
3.
Open wire check (F-CAN A_H line, F-CAN A_L line):

Open wire check (F-CAN A_H line, F-CAN A_L line)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the following connectors.
CAN gateway 16P connector
TCM connector (50P)

?3.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
CAN gateway 16P connector: disconnected
 
TCM connector (50P): disconnected
Test point 1
CAN gateway 16P connector (female terminals) No. 3:
Test point 2
TCM connector (50P) No. 3

Test point 1
CAN gateway 16P connector (female terminals) No. 11:
Test point 2
TCM connector (50P) No. 11


Is there continuity?

     
YES
     
     
     
The F-CAN A_H wire and the F-CAN A_L wire are OK. Check for poor connections or loose terminals at the CAN gateway and the TCM. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or substitute a known-good TCM, then recheck. If this DTC goes away and the TCM was substituted, replace the original TCM.?
     
NO
     
     
     
Repair an open in the F-CAN A_H wire and/or the F-CAN A_L wire between the CAN gateway and the TCM.?