DTC Troubleshooting: U0029, U0100
DTC U0029: F-CAN Malfunction (BUS-OFF)
DTC U0100: F-CAN Malfunction (ACM-PCM)
NOTE: Before you troubleshoot, record all freeze data and any on-board snapshots, and review the general troubleshooting information.

DTC Description
Confirmed DTC
Pending DTC
Freeze Frame
U0029 F-CAN Malfunction (BUS-OFF)
      
U0100 F-CAN Malfunction (ACM-PCM)
      

1.
MIL check:

MIL check
?1.
Press the engine start/stop button to select the ON mode.

?2.
Check the MIL on the gauge control module.

Is the MIL on?

     
YES
     
     
     
     
NO
     
     
     
Go to step 2.
2.
Problem verification:

Problem verification
?1.
Press the engine start/stop button to select 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
U0029 F-CAN Malfunction (BUS-OFF)
      
U0100 F-CAN Malfunction (ACM-PCM)
      

Is DTC U0029 and/or U0100 indicated?

     
YES
     
     
     
Go to step 3.
     
NO
     
     
     
Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the engine mount control unit and the PCM.?
3.
Shorted wire check (F CAN-L line to F CAN-H line):

Shorted wire check (F CAN-L line to F CAN-H line)
?1.
Press the engine start/stop button to select the OFF mode.

?2.
Disconnect the following connector.

?3.
Measure the resistance between test points 1 and 2.
Test condition
OFF mode
Engine mount control unit 16P connector: disconnected
Test circuit
F CAN-L, F CAN-H
Test point 1
Engine mount control unit 16P connector No. 15 (RED)
Test point 2
Engine mount control unit 16P connector No. 13 (WHT)


Is there about 20 ? or more?

     
YES
     
     
     
Go to step 4.
     
NO
     
     
     
Repair a short in the F CAN-L wire to F CAN-H wire between engine mount control unit 16P connector terminals No. 15 and No. 13, then do the repair verification.
4.
Shorted wire check (F CAN-L, F CAN-H lines):

Shorted wire check (F CAN-L, F CAN-H lines)
?1.
Check for continuity between test points and body ground individually.
Test condition
OFF mode
Engine mount control unit 16P connector: disconnect

Connector
Test circuit
Terminal
Engine mount control unit 16P connector
F CAN-L
No. 15 (RED)
F CAN-H
No. 13 (WHT)


Is there continuity at one or both testing positions?

     
YES
     
     
     
Repair a short in the F CAN-L and/or F CAN-H wire between engine mount control unit 16P connector terminal No. 13 and No. 15 and body ground, then do the repair verification.
     
NO
     
     
     
Go to step 5.
5.
Open wire check (F CAN-L, F CAN-H lines):

Open wire check (F CAN-L, F CAN-H lines)
?1.
Press the engine start/stop button to select the OFF mode.

?2.
Jump the SCS line with the HDS.
NOTE: This step must be done to protect the PCM from damage.


?3.
Disconnect the following connector.

?4.
Check for continuity between test points 1 and 2.
Test condition
OFF mode
Engine mount control unit 16P connector: disconnect
PCM connector A (51P): disconnect
Test circuit
F CAN-L
Test point 1
Engine mount control unit 16P connector No. 15 (RED)
Test point 2
PCM connector A (51P) No. 10 (RED)

Test circuit
F CAN-H
Test point 1
Engine mount control unit 16P connector No. 13 (WHT)
Test point 2
PCM connector A (51P) No. 9 (WHT)


Is there continuity?

     
YES
     
     
     
Check for poor connections or loose terminals at the engine mount control unit and the PCM. If it is OK, replace the engine mount control unit, then do the repair verification.
     
NO
     
     
     
Repair an open in the F CAN-L and/or F CAN-H wire between engine mount control unit 16P connector terminal No. 15 and No. 13 and PCM connector terminal A (51P) No. 10 and No. 9, then do the repair verification.
Repair verification:

?1.
Press the engine start/stop button to select the OFF mode.

?2.
Reconnect all connectors.

?3.
Exit the SCS mode with the HDS.


?4.
Press the engine start/stop button to select the ON mode.

?5.
Clear the DTC with the HDS.


?6.
Check for pending or confirmed DTCs with the HDS.
DTC Description
Confirmed DTC
Pending DTC
Freeze Frame
U0029 F-CAN Malfunction (BUS-OFF)
      
U0100 F-CAN Malfunction (ACM-PCM)
      


Is DTC U0029 and/or U0100 indicated?

     
YES
     
     
     
Check for poor connections or loose terminals at the engine mount control unit and the PCM, then go to step 1.
     
NO
     
     
     
Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated DTC's troubleshooting.?