DTC Troubleshooting: U0029-00
DTC U0029-00: CAN Communication Failure (Bus OFF)
NOTE:
This DTC is stored by communication failure between the F-CAN line and the VSA modulator-control unit. When DTC U0029-00 is indicated, the F-CAN line has already returned to normal. Check for loose terminals and poor connections at the connectors. If the connectors are OK, clear the DTC and follow this troubleshooting.
Troubleshoot any PGM-FI system DTCs first.
Before you troubleshoot, review the general troubleshooting information.

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

1.
Problem verification:

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

?2.
Clear the DTC with the HDS.


?3.
Turn the vehicle to the OFF (LOCK) mode.

?4.
Turn the vehicle to the ON mode, then wait for a few seconds or more.

?5.
Check for DTCs with the HDS.
DTC Description
DTC
U0029-00 CAN Communication Failure (Bus OFF)
  

Is U0029-00 indicated?

     
YES
     
     
     
The failure is duplicated. Go to step 2.
     
NO
     
     
     
Intermittent failure, the system is OK at this time. Refer to intermittent failures troubleshooting.?
2.
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
     
     
     
Go to indicated DTC's troubleshooting.?
     
NO
     
     
     
Go to step 3.
3.
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.

  

Does the CAN gateway detect the VSA modulator-control unit Bus channels A and B?

     
 
'16-18
 
2/4-door: VSA modulator-control unit is Not Available for Bus A
     
     
     
Go to step 4.
     
 
'16-18
 
2/4-door: VSA modulator-control unit is Not Available for Bus B
     
     
     
Go to step 5.
     
 
'19-21
 
2/4-door: VSA modulator-control unit is Not Available for Bus A
     
     
     
Go to step 6.
     
 
'19-21
 
2/4-door: VSA modulator-control unit is Not Available for Bus B
     
     
     
Go to step 7.
     
 
'17-19
 
5-door: VSA modulator-control unit is Not Available for Bus A
     
     
     
Go to step 4.
     
 
'17-19
 
5-door: VSA modulator-control unit is Not Available for Bus B
     
     
     
Go to step 5.
     
 
'20-21
 
5-door: VSA modulator-control unit is Not Available for Bus A
     
     
     
Go to step 6.
     
 
'20-21
 
5-door: VSA modulator-control unit is Not Available for Bus B
     
     
     
Go to step 7.
     
VSA modulator-control unit Bus A and B are Available
     
     
     
Check for loose terminals and poor connections in the VSA modulator-control unit connector. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting or replace the VSA modulator-control unit.?
4.
Open wire check (F-CAN A_H, F-CAN A_L lines):

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

?2.
Disconnect the following connectors.
CAN gateway 12P connector
VSA modulator-control unit 46P connector

?3.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
CAN gateway 12P connector: disconnected
 
VSA modulator-control unit 46P connector: disconnected
Test point 1
CAN gateway 12P connector (female terminals) No. 3:
Test point 2
VSA modulator-control unit 46P connector No. 20

Test point 1
CAN gateway 12P connector (female terminals) No. 9:
Test point 2
VSA modulator-control unit 46P connector No. 21


Is there 1.0 ? or less ?

     
YES
     
     
     
The F-CAN A_H and F-CAN A_L wires are OK. Check for loose terminals in the VSA modulator-control unit 46P connector. If the symptom/indication is still present, replace the VSA modulator-control unit.?
     
NO
     
     
     
Repair an open in the wire between the VSA modulator-control unit and the CAN gateway.?
5.
Open wire check (F-CAN B_H, F-CAN B_L lines):

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

?2.
Disconnect the following connectors.
CAN gateway 12P connector
VSA modulator-control unit 46P connector

?3.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
CAN gateway 12P connector: disconnected
 
VSA modulator-control unit 46P connector: disconnected
Test point 1
CAN gateway 12P connector (female terminals) No. 12:
Test point 2
VSA modulator-control unit 46P connector No. 24

Test point 1
CAN gateway 12P connector (female terminals) No. 5:
Test point 2
VSA modulator-control unit 46P connector No. 25


Is there 1.0 ? or less ?

     
YES
     
     
     
The F-CAN B_H and F-CAN B_L wires are OK. Check for loose terminals in the VSA modulator-control unit 46P connector. If the symptom/indication is still present, replace the VSA modulator-control unit.?
     
NO
     
     
     
Repair an open in the wire between the VSA modulator-control unit and the CAN gateway.?
6.
Open wire check (F-CAN A_H, F-CAN A_L lines):

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

?2.
Disconnect the following connectors.
CAN gateway 16P connector
VSA modulator-control unit 46P connector

?3.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
CAN gateway 16P connector: disconnected
 
VSA modulator-control unit 46P connector: disconnected
Test point 1
CAN gateway 16P connector (female terminals) No. 3:
Test point 2
VSA modulator-control unit 46P connector No. 20

Test point 1
CAN gateway 16P connector (female terminals) No. 11:
Test point 2
VSA modulator-control unit 46P connector No. 21


Is there 1.0 ? or less ?

     
YES
     
     
     
The F-CAN A_H and F-CAN A_L wires are OK. Check for loose terminals in the VSA modulator-control unit 46P connector. If the symptom/indication is still present, replace the VSA modulator-control unit.?
     
NO
     
     
     
Repair an open in the wire between the VSA modulator-control unit and the CAN gateway.?
7.
Open wire check (F-CAN B_H, F-CAN B_L lines):

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

?2.
Disconnect the following connectors.
CAN gateway 16P connector
VSA modulator-control unit 46P connector

?3.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
CAN gateway 16P connector: disconnected
 
VSA modulator-control unit 46P connector: disconnected
Test point 1
CAN gateway 16P connector (female terminals) No. 6:
Test point 2
VSA modulator-control unit 46P connector No. 24

Test point 1
CAN gateway 16P connector (female terminals) No. 14:
Test point 2
VSA modulator-control unit 46P connector No. 25


Is there 1.0 ? or less ?

     
YES
     
     
     
The F-CAN B_H and F-CAN B_L wires are OK. Check for loose terminals in the VSA modulator-control unit 46P connector. If the symptom/indication is still present, replace the VSA modulator-control unit.?
     
NO
     
     
     
Repair an open in the wire between the VSA modulator-control unit and the CAN gateway.?