DTC Troubleshooting: U129E
DTC U129E: F-CAN Malfunction (PCM-Power Control Unit (PCU))
NOTE: Before you troubleshoot, review the general troubleshooting information.

DTC Description
Confirmed DTC
Pending DTC
Freeze Frame
U129E F-CAN Malfunction (PCM-Power Control Unit (PCU))
     

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
U129E F-CAN Malfunction (PCM-Power Control Unit (PCU))
     

Is DTC U129E 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 keyless access control 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.
Keyless access system check:

Keyless access system check
?1.
Check for communication to the keyless access system with the HDS.

Does the HDS communicate with the keyless access 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.


?3.
Disconnect the following connectors.
PCM connector A (51P)
Keyless access control unit connector C (20P)

?4.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
PCM connector A (51P): disconnected
Keyless access control unit connector C (20P): disconnected
Test point 1
Keyless access control unit connector C (20P) 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 keyless access control 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
Keyless access control unit connector C (20P): disconnected
Test point 1
Keyless access control unit connector C (20P) No. 12
Test point 2
PCM connector A (51P) No. 1

Is there continuity?

     
YES
     
     
     
The F-CAN_L wire is OK. Substitute a known-good keyless access control unit, then recheck. If DTC U129E is not indicated after substitution, replace the original keyless access control unit.?
     
NO
     
     
     
Repair an open in the F-CAN_L wire between the PCM (A1) and the keyless access control unit.?