DTC Troubleshooting: U0029-00
DTC U0029-00: CAN Communication Failure (Ch1 Bus OFF)
NOTE:
Before you troubleshoot, review the general troubleshooting information.
This DTC is stored by communication failure between the F-CAN line and the electric brake booster. When DTC U0029-00 is indicated, the F-CAN line has already returned to normal. Check for loose terminals and poor connections in the connectors. If the connectors are OK, clear the DTC and following this troubleshooting.

DTC Description
DTC
Freeze Frame
U0029-00 CAN Communication Failure (Ch1 Bus OFF)
    

1.
Electric brake booster communication check:

Electric brake booster communication check
?1.
Turn the vehicle to the ON mode.

?2.
Check for communication between the electric brake booster and the HDS.

Is there communication between the electric brake booster and the HDS?

     
YES
     
     
     
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.?
     
NO
     
     
     
Go to step 2.
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 with driver's door open.

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


?3.
Wait for 3 minutes.
NOTE: Do not close the driver's door.

?4.
Disconnect the following connectors.
Electric brake booster 26P connector
PCM connector A (51P)

?5.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
Electric brake booster 26P connector: disconnected
 
PCM connector A (51P): disconnected
Test circuit 1
  
Test point 1
Electric brake booster 26P connector No. 26
Test point 2
PCM connector A (51P) No. 2

Test circuit 2
  
Test point 1
Electric brake booster 26P connector No. 18
Test point 2
PCM connector A (51P) No. 1

Is there continuity?

     
YES
     
     
     
The F-CAN_H and F-CAN_L wires are OK. Check for loose terminals and poor connections in the electric brake booster 26P connector. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting. If they are OK, replace the electric brake booster.?
     
NO
     
     
     
Repair an open in the wire between the electric brake booster and the PCM.?