ISX 871 error 2449

[Lead_sled]

Got an error message yesterday and curious to know why. I’ve already ordered a new VGT actuator to replace it.

The error only comes on when engine brake is on and coming to a stop. Neither actuator or turbo has been changed recently.

After message is activated, I can turn engine off and restart with no error message. Can also run truck without engine brake and it not reactivate.

Any ideas? I’ll change the actuator, but just want to be sure I’m chasing the right issue.

Does the back pressure sensor have anything to do with this?