When we arrived at the Las Cruces KOA, we got the Check Engine and Malfunction Indicator Lights on our dash, and the three error codes that indicated the dreaded DEF head failure issue — SPN 3364 FMI 9, SPN 1761 FMI 9, and SPN 3031 FMI 9:

We tried to reset the errors with the BlueFire adapter, which worked… but at the end of the next drive, the errors came back. So we knew we had to get the DEF head replaced. The DEF head is a component of the Diesel Exhaust Fluid system, that measures the level and temperature of the DEF tank. But coaches built around 2017, as ours was, had a part with a design flaw, causing it to fail for many coaches. It was pretty much a matter of time before ours failed, so I got a DEF head simulator as insurance, and we never let the DEF get below halfway, to help reduce the chance of the issue occurring. But our time came regardless.

We could have taken our coach to a Cummins service shop, but they operate on a first-come-first-served basis, so we’d likely have to wait a few days. Not convenient when we live full-time in our coach. But fortunately we were a few hours south of Phoenix, Arizona, where National Indoor RV Centers (NIRVC) has a facility. A place we were familiar with, having had our coach serviced there before.

So I contacted that NIRVC, and asked if they could get the replacement DEF head from Tiffin, and fit us in to replace it. They were able to do so. We were super-impressed with their service. They worked with Tiffin to get the part overnighted, and Tiffin covered the cost of the part and labor. When we arrived, the Service Manager (Andrew Pringle) greeted me and came out to help us get parked in a campsite.

We also got them to do a few other tweaks while we were there. One was I noticed this pump/compressor/thingy that’s part of the air leveling system had come off its brackets, and was vibrating significantly when used (we pretty much never use air leveling, but tried it when arriving at NIRVC; great time to find that!):

The brackets were broken, so the tech drilled out and replaced the brackets to get it re-mounted.

We also got them to look for a rattling noise elsewhere in the generator compartment, which they partially fixed with some foam padding. And we got them to add a cover over the ceiling vent in our rear bathroom; something we wanted to do at the recent NIRVC service in Dallas, but the part was out-of-stock there.

Not bad for a day’s work at short notice!

We had been scheduled to stay in Tombstone for seven days, but we left early to go to NIRVC, arriving in the afternoon, and staying overnight at NIRVC, so they could have the full next day to do their work. We chose to stay there that night too, before moving on.

Here are my usual campsite stats; not a typical campsite, but great that NIRVC offers the ability to stay overnight, even with an electrical hookup:

Dates:

• Check in: 2023-03-08
• Check out: 2023-03-10
• 2 nights

Weather:

• Mostly sunny
• High temps ranging between 75°F, lows around 42-44°F
• Negligible wind

Noise:

• Some road noise, no train noise
• Jets flying over from Luke Air Force Base

Site:

• #4, back in, gravel
• Needed to disconnect toad; parked beside coach
• Fairly level
• Medium site: about 70 feet long by about 25 feet wide

Utilities:

• 50 amp power, conveniently located
• No water
• No sewer (dump station available)

Internet (in usage priority order):

• T-Mobile: 62-75 Mbps down, 30 Mbps up, 80 ms ping
• AT&T: 33-49 Mbps down, 12 Mbps up, 70 ms ping
• Verizon: 47-70 Mbps down, 20-41 Mbps up, 60 ms ping
• Starlink: not used
• Campground Wi-Fi: none

Amenities:

• RV repair

Interactive map; the campsites are in the northeast corner of the grounds:

Our site (with the generator compartment open):

Electrical hookup:

Looking past our site to the front of the NIRVC building:

We sat in the waiting room for a few hours:

Kitchen:

The waiting room has windows overlooking the massive indoor RV storage facility:

Looking across the storage area, you can see the roof of our coach by the leftmost door:

We were very happy with their service, glad that they could fit us in, and solve our DEF head issue plus the other improvements. We highly recommend NIRVC for RV service.