I�ve got a 2016 year model with around 23k miles on it. A couple weeks ago I got a 500 mile warning for adding DEF. I added 2.5 gallons of the Peak Blue DEF I�ve been using since I got the truck. A few days ago I got the same 500 mile warning. I had just added the 2.5 gallons so I knew I wasn�t low. I topped the DEF off with another 2 gallons. The warning light is back on after being off for one day.

I visited a Ford Super Duty forum and apparently there�s an issue with this warning. The consensus was drive it until it gets under the 200 mile warning. If it doesn�t go off, take it to the Ford dealership and have them reset it for you.

Any other advice or wisdom from the TFF experts?

Thanks

Jimmy

I have had a few of these pickups, and they all had a hiccup with that at some point. The worst ones are the ones that sit a lot and don�t rack up many miles. What I found is to wait until the 500 to empty comes on, fill it up all the way and it usually won�t bother you again. I found by just adding some, the sensor does not always notice it. It is my belief that that stuff makes the sensor get stuck at times, and when it is refilled it rattles it loose again.

Mine (a 2012 though) had a bad DEF sensor and would keep throwing the code/light. Then I also lost the DEF heater, luckily extended warranty covered both items.

One of the reasons guys delete and bypass these trucks.

The first time my personal truck gives me any static that requires repair, this is happening.

The service manager at my local Ford dealer told me that he would never see powerstrokes if the DPF didn�t puke every 75k. He hasn�t seen my truck since.

That's weird, I have a few units in my fleet with well over 300,000 miles on the DPF's. I hate the whole after treatment systems, we now have them on 2500 HP V-16's on our pumps. They suck.

Your fleet trucks are probably run a lot and used for what they were designed for. Lots of people buying those tucks that don't own a trailer and commute 5 miles is a lot of the problem I believe.

Yeah, that has a lot to do with it. Sometimes I forget people actually buy these to make a 5 mile urban commute.

To close the loop....I�m retired. I don�t drive mine every day. I pull a 10k, 35 ft travel trailer with my truck. The week before I got the warning, we went on a 10 day, 1,200 mile trip pulling the trailer. Truck did great. 68-70 mph in 90+ temps.

Jimmy

Something else to consider is that DEF has a useful shelf life, I believe it is like 6 months and if stored in a hot environment or exposed to sunlight can be shorter. A 2016 with 23k mile son it makes me think you don't go through a lot of it.

I don't know what the trucks strategy is for dealing with old, stale, etc. def. Does it just use more till it gets what it wants? Is there some type of DEF quality sensor?

Be interesting to hear if anyone knowns.

Oh yes, it has a sensor. You will get a check engine light, and when you hook up Detroit DL, Cummins Insite or CAT ET, you will get the code for Low DEF Quality. It takes in the data of DEF used and compares it to the differential of the SCR inlet vs. outlet of the exhaust. When it sees DEF used and no cleanup, you get the code. It is very unreliable, when you get the code, it is normally another problem. I have yet to actually have DEF fail the Hydrometer test. I buy 3000 gallons of DEF every month, and store it in 1000 gallon tanks with pump and meter setups. DEF stays good a long time, one of my guys forgot about a 330 gallon tote of it we had, and it sat outside for over a year. It tested good, and we ran it with no issues. I also had to park 35% of the fleet during a down turn, they sat still for 18 months, and no problems. I do believe if you had a low tank, and it was able to crystallize enough, it would cause issues.