...you sure you didn't take the truck to a Ford dealer by mistake...that kind of treatment is typical Ford style customer dis-service...
DEF is a product mixed to industry standards...it's all the same formula...denying warranty coverage for DEF purchased at a location other than a GM/Ford/Ram dealership would be tantamount to denying warranty for using an engine oil other than their house brand...
...coincidentally, I am currently in Iowa building a truck stop. The diesel fuel is unbranded. We just installed a 7500 gallon DEF underground storage tank. The diesel islands have dispensed DEF at each diesel dispenser. The DEF is provided by Diamond DEF. If warranty denial as shown by the crooked dealer he Op visited, why are bulk DEF sales so successful?
.as we bury all these tanks, they have to be filled to 95% capacity with product to keep the tanks from potentially floating...looks like this DEF and all the fuel will be over 90 days old before we pump a gallon out of the tanks...shelf life?????
Regards