DTC Troubleshooting: U1281-00, U1291-00
DTC U1281-00: Lost Communication with The MICU (Body Control Module)
DTC U1291-00: Lost Communication with The Relay Control Module
NOTE:
Before you troubleshoot, review the general troubleshooting information.
The DTC may be stored due a poor ground or power source failure at the transmitting control unit.
Inspection of the power and grounds for each control unit is required prior to proceeding with this troubleshooting.
The MICU controls the windshield wiper operation on this vehicle.

DTC Description
DTC
Freeze Frame
U1281-00 Lost Communication with The MICU (Body Control Module)
    
U1291-00 Lost Communication with The Relay Control Module
    

1.
Problem verification:

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

?2.
Clear the DTCs with the HDS.


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

?4.
Turn the vehicle to the ON mode, then wait for at least 2 seconds.

?5.
Check for DTCs with the HDS.
DTC Description
DTC
Freeze Frame
U1281-00 Lost Communication with The MICU (Body Control Module)
    
U1291-00 Lost Communication with The Relay Control Module
    

Are any DTCs indicated?

     
YES
     
     
     
Go to step 2.
     
NO
     
     
     
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.?
2.
Open wire check (B-CAN_H line, B-CAN_L line):

Open wire check (B-CAN_H line, B-CAN_L line)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the following connectors.
Multipurpose camera unit 20P connector
Under-dash fuse/relay box connector G (10P)

?3.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
Multipurpose camera unit 20P connector: disconnected
 
Under-dash fuse/relay box connector G (10P): disconnected



Is there continuity?

     
YES
     
     
     
The B-CAN_L and B-CAN_H wires are OK. Faulty MICU; replace the under-dash fuse/relay box.?
     
NO
     
     
     
Repair an open in the B-CAN_H wire and/or the B-CAN_L wire between the multipurpose camera unit and the MICU.?