DTC Troubleshooting: U0100-00, U0101-00
DTC U0100-00: CAN Communication Failure With ECM/ISU
DTC U0101-00: CAN Communication Failure With TCM
NOTE:

DTC Description
DTC
Freeze Frame
U0100-00 CAN Communication Failure With ECM/ISU
    
U0101-00 CAN Communication Failure With TCM
    

1.
DTC check:

DTC check
?1.
Turn the vehicle to the ON mode.

?2.
Clear the DTC with the HDS.


?3.
Turn the vehicle to the OFF (LOCK) mode, then start the engine.

?4.
Test-drive the vehicle at 6 mph (10 km/h) or more.
NOTE: Drive the vehicle on the road, not on a lift.

?5.
Check for DTCs with the HDS.
DTC Description
DTC
Freeze Frame
U0029-00 CAN Communication Failure (Bus OFF)
    
U0100-00 CAN Communication Failure With ECM/ISU
    
U0101-00 CAN Communication Failure With TCM
    

Is DTC U0100-00 or U0101-00 indicated?

     
YES
     
     
     
If only DTC U0100-00 or U0101-00 are indicated, go to step 2.
     
YES
     
     
     
If DTC U0029-00 is also indicated, go to DTC U0029-00.?
     
NO
     
     
     
Intermittent failure, the system is OK at this time. Refer to intermittent failures troubleshooting. 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.
Open wire check (F-CAN_H, F-CAN_L lines):

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

?2.
Short the SCS line with the HDS.


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

?4.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
VSA modulator-control unit 38P connector: disconnected
 
PCM connector A (51P): 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 and F-CAN_L wires are OK. Go to step 3.
     
NO
     
     
     
Repair an open in the wire between the PCM and the VSA modulator-control unit.?
3.
PCM check (update or substitution):

PCM check (update or substitution)
?1.
Reconnect the following connectors.
VSA modulator-control unit 38P connector
PCM connector A (51P)

?2.
Update the PCM if it does not have the latest software, or substitute a known-good PCM.

?3.
Clear the DTC with the HDS.


?4.
Turn the vehicle to the OFF (LOCK) mode, start the engine.

?5.
Test-drive the vehicle at 6 mph (10 km/h) or more.
NOTE: Drive the vehicle on the road, not on a lift.

?6.
Check for DTCs with the HDS.
DTC Description
DTC
Freeze Frame
U0100-00 CAN Communication Failure With ECM/ISU
    
U0101-00 CAN Communication Failure With TCM
    

Is DTC U0100-00 or U0101-00 indicated?

     
YES
     
     
     
Go to step 4.
     
NO
     
     
     
If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM.?
4.
VSA modulator-control unit check (update):

VSA modulator-control unit check (update)
?1.
Update the VSA modulator-control unit if it does not have the latest software.

?2.
Turn the vehicle to the OFF (LOCK) mode, then start the engine.

?3.
Test-drive the vehicle at 6 mph (10 km/h) or more.
NOTE: Drive the vehicle on the road, not on a lift.

?4.
Check for DTCs with the HDS.
DTC Description
DTC
Freeze Frame
     

Is DTC U0100-00 or U0101-00 indicated?

     
YES
     
     
     
Check for loose terminals and poor connections in the VSA modulator-control unit 38P connector. If the VSA modulator-control unit was updated and the symptom/indication is still present, replace the VSA modulator-control unit.?
     
NO
     
     
     
Troubleshooting is complete. If any other DTCs are indicated, go to the indicated DTCs troubleshooting.?