2018 Newmar Dutch Star

When preparing to leave, my coach received a check engine light, and 3 error codes from the Cumins ECU. SPN 3364, 1761 and 3031. All FMI code 9. My engine is Likely now debated to 5% power and I was just able to return it to the driveway at the house. Thankfully I hadn’t gotten onto the busy interstate when it happened. After contacting Spartan Chassis, they informed me that I needed a new DEF Head unit. This has been a major issue across the industry. The part is manufactured by SHAW and parts are not available. I was told by Spartan “August or September” for parts. I am unable to move the coach for fear that it is in fact debated to 5% so will need to have a mobile mechanic dispatched to replace. I understand the need for emission controls, but to derate the engine because we might have a little bit dirtier tailpipe until its fixed…. Major safety issue as there is NO workaround.

Since purchasing this RV new, I have had the DEF Head fail twice. 1st time was Sep 2019 with a mileage of 14066 and the 2nd time was April 2021 with a mileage of 16018. Both times DEF Header Assemblies were replaced. When these fail the motor can de-rate at any time. Very dangerous when traveling down the highway. Both times the low DEF warning and check engine lights came on.

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.

The failure has occurred in the emission system. The DEF SENSOR set off 2 Check Engine light warnings on the dash. It did not tell me any other information. I was fortunate to return from my trip without incident. However, after speaking with the chassis manufacturer (Spartan), I was fortunate to be able to continue. Had I gone any further the engine would have begun a shutdown leaving my 24 ton RV stranded roadside. It could have been very serious breakdown on a metro highway causing major traffic jams or left stranded in a remote location. The component required for replacement is not available till late Aug or Sept. As we live full time in the RV we are now stranded unable to travel until the part is available. Although our example appears to be an inconvenience we have dozens of other RVers experiencing this same problem and unaware of being stranded until the failure occurs. Whatever is causing the failure of these DEF sensors, owners should be notified and a general recall for replacement should be issued.

Shortly after departing from J&J RV Park in Hot Springs, Arkansas, in my vehicle, a motorhome, two yellow check-engine lights illuminated on the dashboard. I continued driving for 52 miles to my next destination, Downtown Riverside RV Park in North Little Rock, Arkansas. The engine ran normally, and I arrived safely. I checked the vehicle's computer system on the dashboard and located three trouble codes: 3364, 1761, and 3031. I contacted the vehicle's chassis manufacturer, Spartan Chassis in Charlotte, Michigan, and was told the codes indicated the vehicle's Diesel Exhaust Fluid (DEF) head was defective and needed to be replaced. The gentleman told me not to drive the motorhome and to remain in a safe haven off the road, which in my case is the RV park. He said the limited number of DEF heads in Spartan's inventory are being held for customers whose engines have displayed red stop-engine lights, gone into limp mode and stranded the customers on the side of a road. Those customers receive a new DEF head by overnight mail, are back on the road within a couple days and are able to continue their normal travels. The limited inventory does not allow for customers like me who are not broken down somewhere to receive the DEF head quickly. Spartan's inventory is not anticipated to be replenished until sometime in August 2021. Therefore, if I choose to follow Spartan's recommendation, which I plan to do, I have to cancel campground reservations and summer travel plans and stay in place for at least two months. I'm on a waiting list to receive the part. This is a well-known, long-term problem on motorhomes manufactured by Spartan and other companies, and is supposedly affecting the trucking industry. It has been much discussed on online forums. Spartan's DEF head is produced by Shaw Development LLC in Bonita Springs, Florida. The problem has not been confirmed by a local dealer or independent service center. The vehicle is available for inspection.

Diesel Exhaust Fluid Control unit failed 04/28/21 @ 21,151 miles. Unfortunately this can cause the motor to de-rate with speed restricted to 5mph. Very dangerous on the freeway. Problem was confirmed by the Cummins codes generated and verified by both Spartan motors as well as the repair facility that performed the repair. No warning lamps, symptoms, or messages prior to the failure.

DEF SYSTEM FOR DIESEL ENGINE STARTED TO FAIL CAUSING REDUCTION IN PERFORMANCE OF MOTOR HOME. IF I HAD NOT BEEN ABLE TO GET DIRECTLY TO A FREIGHTLINER SERVICE CENTER, I WOULD HAVE ENDED UP ON THE INTERSTATE ABLE TO GO ONLY FIVE MILES PER HOUR AND NEEDING TO BE TOWED. THIS IS AN ON GOING KNOWN PROBLEM WITH THESE ENGINES MANUFACTURED BY CUMMINS. THIS PARTICULAR PART IS FAILING ON A REGULAR BASIS ACROSS MANY CHASSIS MAKERS CAUSING A POTENTIAL DANGER TO THE OWNERS OF THESE COACHES. THE PARTICULAR PART IS CALLED A DEF HEAD THAT REGULATES AND METERS THE POLLUTION REDUCING DEF FLUID. THIS PART NEEDS TO BE IMPROVED AND IF IT DOES FAIL, A BETTER SOLUTION NEEDS TO BE IMPLEMENTED THAT DOES NOT DERATE THE ENGINE PERFORMANCE TO THE POINT OF BEING DISABLED LEAVING PEOPLE STRANDED.