NHTSA Complaint #11425312 — 2018 NEWMAR DUTCH STAR

We got the check engine light on after starting up our coach on July 6. We got several fault codes: SPN 3364 FMI 9, SPN 1761 FMI 9, SPN 3031 FMI 9. The codes indicated that we had a faulty DEF Header and it needed to be replaced. And if we drove the coach at some point it would "derate" to 5 miles an hour and we would not be able to drive it. We were told by the chassis maker (Spartan) that we would likely not be able to get a replacement part until September or October due to the global microchip shortage. And even though there was nothing actually wrong with engine or the DEF (we had a full tank) there was no work around. Because we were in West Yellowstone where there was no diesel engine service nor a place we could leave the coach for several months. We decided to drive the coach to our next destination, Lander Wyoming which had two Cummins engine shops. We made it there, but then got the "stop engine" code - SPN 5246 FMI 16. The coach derated and we could no longer drive it. The Cummins service shop was able to clear the "stop engine" code, so we could drive it. But the check engine codes would remain until the DEF header was replaced. And countdown would restart to "stop engine". On the irv2.com RV blog forum, Spartan chassis owners, with Shaw DEF headers have reported the DEF header failure. A number have had multiple failures. Since it seems as though it may be months before a supply of DEF headers will be readily available and there is nothing fundamentally wrong with the engine, it would be tremendously helpful for Cummins or Spartan to design a workaround while the parts supply is rebuilt and it seems likely that Shaw needs to redesign their DEF Header to reduce the failure rate or Spartan needs to find a new supplier.