DTC Troubleshooting: U0122
DTC U0122: F-CAN Malfunction (PCM-VSA Modulator-Control Unit)
NOTE: Before you troubleshoot, review the general troubleshooting information.

DTC Description
Confirmed DTC
Pending DTC
Freeze Frame
U0122 F-CAN Malfunction (PCM-VSA Modulator-Control Unit)
      

1.
Problem verification:

Problem verification
?1.
Turn the vehicle to the ON mode.

?2.
Clear the DTC with the HDS.


?3.
Check for Pending or Confirmed DTCs with the HDS.
DTC Description
Confirmed DTC
Pending DTC
Freeze Frame
U0122 F-CAN Malfunction (PCM-VSA Modulator-Control Unit)
      

Is DTC U0122 indicated?

     
YES
     
     
     
The failure is duplicated. Go to step 2.
     
NO
     
     
     
Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the VSA modulator-control unit and the PCM. 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.?
2.
VSA system check:

VSA system check
?1.
Check for communication to the VSA system with the HDS.

Does the HDS communicate with the VSA system?

     
YES
     
     
     
Go to step 3.
     
NO
     
     
     
3.
Open wire check (F-CAN_H line):

Open wire check (F-CAN_H line)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Jump the SCS line with the HDS.


?3.
Disconnect the following connectors.
PCM connector A (51P)
VSA modulator-control unit 38P connector

?4.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
PCM connector A (51P): disconnected
 
VSA modulator-control unit 38P connector: disconnected
Test point 1
VSA modulator-control unit 38P connector No. 38
Test point 2
PCM connector A (51P) No. 2

Is there continuity?

     
YES
     
     
     
The F-CAN_H wire is OK. Go to step 4.
     
NO
     
     
     
Repair an open in the F-CAN_H wire between the PCM (A2) and the VSA modulator-control unit.?
4.
Open wire check (F-CAN_L line):

Open wire check (F-CAN_L line)
?1.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
PCM connector A (51P): disconnected
 
VSA modulator-control unit 38P connector: disconnected
Test point 1
VSA modulator-control unit 38P connector No. 26
Test point 2
PCM connector A (51P) No. 1

Is there continuity?

     
YES
     
     
     
The F-CAN_L wire is OK. Update the VSA modulator-control unit if it does not have the latest software, then recheck. If DTC U0122 is indicated after updated, replace the VSA modulator-control unit.?
     
NO
     
     
     
Repair an open in the F-CAN_L wire between the PCM (A1) and the VSA modulator-control unit.?