We bought this MH used; it had 10000 miles registered. We bought it in Florida and started the trip back to Tennessee. We had driven about 100 miles and the check engine warning said the DEF was low. The DEF gauge showed 8.75 gals. When I got to the truck stop I openrd the bay and the guage still showed 8.75 gal. I filled the tank and drove home. I took the MH to TAG, Jackson Tennessee and they checked the computer, it had one recall for something about the air valves which they fixed free. The other was the sensor board on the DEF tank was not working. They replaced the senson at a cost of $2200.00. TAG told me this was a recurring problem and they had fixed many of sensor defaults. I assume the frame manufacturer furnishes the complete assembly, the frame was a Fleetwood. This is a problem that is causing problems and the cost is way to high and will more than likely have to be replaced again.