DTC Troubleshooting: U0100, U0122, U0155
DTC U0100: F-CAN Malfunction (TCM - FI Control Module)
DTC U0122: Lost Communication With Vehicle Dynamics Control Module
DTC U0155: Lost Communication With Gauge Control Module
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.
Refer to the DTC shown on the display, then inspect the connectors and terminals based on the instructions.
According to the detected DTC(s), check for the power circuit and the ground circuit of the control unit which cannot communicate with the TCM.

DTC Description
Confirmed DTC
Pending DTC
Freeze Frame
U0100 F-CAN Malfunction (TCM - FI Control Module)
      
U0122 Lost Communication With Vehicle Dynamics Control Module
      
U0155 Lost Communication With Gauge Control Module
      

1.
CAN gateway system DTC check:

CAN gateway system DTC check
?1.
Turn the vehicle to the ON mode.

?2.
Check for CAN gateway system DTCs with the HDS.
DTC Description
DTC
U0029-00 CAN Gateway F-CAN ch A Bus Off
  
U0047-00 CAN Gateway F-CAN ch B Bus Off
  
U3000-49 CAN Gateway Internal Failure
  


Is DTC U0029-00, U0047-00, and/or U3000-49 indicated?

     
YES
     
     
     
     
NO
     
     
     
Go to step 2.
2.
F-CAN circuit communication check (Receiving control unit):

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

  

Does the TCM detect the CAN gateway Bus channels A?

     
Bus A is Not Available
     
     
     
Go to step 3.
     
Bus A is Available
     
     
     
Go to step 4.
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 12P connector
TCM 50P connector

?3.
Check for continuity between test points 1 and 2.
F-CAN A_H line
Test condition
Vehicle OFF (LOCK) mode
 
CAN gateway 12P connector: disconnected
 
TCM 50P connector: disconnected
Test point 1
CAN gateway 12P connector No. 3
Test point 2
TCM 50P connector No. 3

F-CAN A_L line
Test condition
Vehicle OFF (LOCK) mode
 
CAN gateway 12P connector: disconnected
 
TCM 50P connector: disconnected
Test point 1
CAN gateway 12P connector No. 9
Test point 2
TCM 50P connector 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 indicated DTC goes away and the TCM was substituted, replace the original TCM.?
     
NO
     
     
     
Repair an open in the F-CAN A_H wire or the F-CAN A_L wire between the TCM and the CAN gateway.?
4.
F-CAN circuit communication check (Transmitting control unit):

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

  

?2.
According to the detected DTC on the following table, make sure that the transmitting control unit detects the CAN gateway Bus channel(s) normally.
DTC
Transmitting control unit
Detected CAN getaway Bus channel(s) at normal
U0100
PCM
A, B
U0122
VSA modulator-control unit
A, B
U0155
Gauge control module
A

Is it detected normally?

     
Detected normal
     
     
     
Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the transmitting control unit and the CAN gateway.?
     
U0100: PCM is Not Available for Bus A
     
     
     
Go to step 5.
     
U0100: PCM is Not Available for Bus B
     
     
     
Go to step 6.
     
U0122: VSA modulator-control unit is Not Available for Bus A
     
     
     
Go to step 5.
     
U0122: VSA modulator-control unit is Not Available for Bus B
     
     
     
Go to step 6.
     
U0155: Gauge control module is Not Available for Bus A
     
     
     
Go to step 5.
5.
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.
U0100: Jump the SCS line with the HDS, and wait more than 1 minute.


?3.
According to the detected DTC on the following table, disconnect the transmitting control unit connector(s).
DTC
Connector
-
CAN gateway 12P connector
U0100
PCM connector A (50P)
U0122
VSA modulator-control unit 46P connector
U0155
Gauge control module connector A (32P)

?4.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
CAN gateway 12P connector: disconnected
 
Transmitting control unit connector(s) for indicated DTCs: disconnected

DTC
Circuit name
Test point 1 (Receiving control unit)
Test point 2 (Transmitting control unit)
Connector
Terminal
Connector
Terminal
U0100
F-CAN A_H
CAN gateway 12P connector
No. 3
PCM connector A (50P)
No. 37
F-CAN A_L
No. 9
No. 36
U0122
F-CAN A_H
CAN gateway 12P connector
No. 3
VSA modulator-control unit 46P connector
No. 20
F-CAN A_L
No. 9
No. 21
U0155
F-CAN A_H
CAN gateway 12P connector
No. 3
Gauge control module connector A (32P)
No. 19
F-CAN A_L
No. 9
No. 20


Is there continuity?

     
YES
     
     
     
The F-CAN A_H wire and the F-CAN A_L wire are OK. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting.
According to the detected DTC on the following table, substitute or replace the correspond control unit.?
DTC
Operation for transmitting control unit
U0100
Check for poor connections or loose terminals at the CAN gateway and the PCM. Substitute a known-good PCM, then recheck. If this DTC goes away and the PCM was substituted, replace the original PCM.?
U0122
Check for poor connections or loose terminals at the CAN gateway and the VSA modulator-control unit. Replace the VSA modulator-control unit.?
U0155
Check for poor connections or loose terminals at the CAN gateway and the gauge control module. Substitute a known-good gauge control module, then recheck. If this DTC goes away and the gauge control module was substituted, replace the original gauge control module.?
     
NO
     
     
     
Repair an open in the F-CAN A_H wire or the F-CAN A_L wire between the transmitting control unit and the CAN gateway.?
6.
Open wire check (F-CAN B_H line, F-CAN B_L line):

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

?2.
U0100: Jump the SCS line with the HDS, and wait more than 1 minute.


?3.
According to the detected DTC on the following table, disconnect the transmitting control unit connector(s).
DTC
Connector
-
CAN gateway 12P connector
U0100
PCM connector A (50P)
U0122
VSA modulator-control unit 46P connector

?4.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
CAN gateway 12P connector: disconnected
 
Transmitting control unit connector(s) for indicated DTCs: disconnected

DTC
Circuit name
Test point 1 (Receiving control unit)
Test point 2 (Transmitting control unit)
Connector
Terminal
Connector
Terminal
U0100
F-CAN B_H
CAN gateway 12P connector
No. 12
PCM connector A (50P)
No. 39
F-CAN B_L
No. 5
No. 38
U0122
F-CAN B_H
CAN gateway 12P connector
No. 12
VSA modulator-control unit 46P connector
No. 24
F-CAN B_L
No. 5
No. 25


Is there continuity?

     
YES
     
     
     
The F-CAN B_H wire and the F-CAN B_L wire are OK. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting.
According to the detected DTC on the following table, substitute or replace the correspond control unit.?
DTC
Operation for transmitting control unit
U0100
Check for poor connections or loose terminals at the CAN gateway and the PCM. Substitute a known-good PCM, then recheck. If this DTC goes away and the PCM was substituted, replace the original PCM.?
U0122
Check for poor connections or loose terminals at the CAN gateway and the VSA modulator-control unit. Replace the VSA modulator-control unit.?
     
NO
     
     
     
Repair an open in the F-CAN B_H wire or the F-CAN B_L wire between the transmitting control unit and the CAN gateway.?