2010 Prostar Retarder code

Hi,

I have a 2010 Intl Prostar with a Cummins engine.

There were no problems with this truck but today drivers reported engine warn and the amber triangle light being on at the same time while driving.

Truck was shutting down every 2-3 miles but never gave a red stop signal.

When the truck is idling, no lights are on

Somehow we made it to the nearest TA and they hooked it up and found a retarder code. They were very unspecific since they couldn't do anything about it.

With the symptoms and that poor diagnose, can anybody explain this situation more professionally?

At least what can be wrong with the retarder and is it a quick fix, costly, cheap...

Thank you!!!

 

Just got it to a Intl dealer. They found two active codes: SPN3981 and SPN3987. Waiting for estimate...