DTC Troubleshooting: U0104
DTC U0104: F-CAN Malfunction (PCM-ACC Unit/Multipurpose Camera Unit)
NOTE: Before you troubleshoot, review the general troubleshooting information.

DTC Description
Confirmed DTC
Pending DTC
Freeze Frame
U0104 F-CAN Malfunction (PCM - ACC Unit/Multipurpose Camera 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
U0104 F-CAN Malfunction (PCM - ACC Unit/Multipurpose Camera Unit)
      

Is DTC U0104 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 multipurpose camera 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.
ACC system check:

ACC system check
?1.
Check for communication to the Integrated Driver Support system with the HDS.

Does the HDS communicate with the Integrated Driver Support 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, and wait more than 1 minute.


?3.
Disconnect the following connectors.
PCM connector A (51P)
Multipurpose camera unit 20P connector

?4.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
PCM connector A (51P): disconnected
 
Multipurpose camera unit 20P connector: disconnected
Test point 1
Multipurpose camera unit 20P connector No. 2
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 multipurpose camera 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
 
Multipurpose camera unit 20P connector: disconnected
Test point 1
Multipurpose camera unit 20P connector No. 13
Test point 2
PCM connector A (51P) No. 1

Is there continuity?

     
YES
     
     
     
The F-CAN_L wire is OK. Update the multipurpose camera unit if it does not have the latest software, or substitute a known-good multipurpose camera unit, then recheck. If DTC U0104 goes away and the multipurpose camera unit was updated, troubleshooting is complete. If DTC U0104 goes away and the multipurpose camera unit was substituted, replace the original multipurpose camera unit.?
     
NO
     
     
     
Repair an open in the F-CAN_L wire between the PCM (A1) and the multipurpose camera unit.?