OK,

my 2016 F350 is in the 500 mile def countdown. Not sure why. There is 5500 miles on it. At about 3K miles, I got the under half full indication, so I put 2.5 gallons in, and it reset. Now at 5500, im getting the under 500 miles countdown, so I bought a couple 2.5 gallon jugs of DEF. Only one would go in. Countdown is still occurring.....

I know there have been prior posts, and will do that search now, but any quick ideas? I'm camping, am less than 500 miles from home, but dont want to be stranded...

 

It can take some driving to reset. Others have noted that the system doesn't always immediately reset.

Bruce

 

Thanks Bruce. Been reading prior posts. My 2011 never had this issue. I hope it clears itself. Never got the under 1/2 indication either.

 

I never let mine go below half but other say you should run it near empty before refilling.

Bruce

 

In my 2011, when I got that message, I'd wait a little while then add a full 2.5 gallon jug. I read all the posts about confusing the system, and that I need to let it run down, then fill it, but never experienced it before. I hope thats all it is.

 

I checked mine at about 5000 miles and it said under half full...(which in reality didn't tell me shnit) At about 6200 miles I put a full 2.5 gallon jug in. room for more? probably but didn't have another jug to find out how much more. So am I just over half now? or am I 3/4 full, close to full? Fail on the DEF gauge Ford.

Ford really should put an accurate gauge in for the DEF fluid. Being such an integral factor in the emissions/exhaust system. If low fluid can put the truck into limp mode, it should have an accurate gauge. Like seriously... would anyone want a fuel gauge that just said, "Fuel tank is less than half full"?

 

I think all manufacturers in our truck segment fake actual DEF levels. It's a few sensors. I agree it's annoying.

My only advice is that when you fill it, fill it all the way so that you know you hit the top sensor. I've kept my topped off without issues, but usually I just let the below 1/2 full message hit and then I top it all the way off. Usually I can JUST about fit a 2.5 gal. jug in, if I can't, I drive it a little more and dump the rest in. Rather not have a little bit of DEF sitting in a big jug if I can help it. This is just my .02.

The reason, is that one time I had to go through several drive cycles before it reset the countdown to idle in my 2015. I only saw the 800 miles to empty in my 2011 once and it reset right away. (now of course it's 500) I was close to calling the dealer and then it reset.

This is something I think Ford could do a better job with - maybe they did with the 2017s, but something tells me that they left it alone.

 

I think the system is confused. Let it run down almost to zero and see if it resets, otherwise a trip to the dealer.

I run mine down to less than 200 and then do the refills. Never been any problems.

 

Well what happens at zero? Speed limited? shutdown?

 

If you get to zero It will derate. Obviously it will run dry and now you have a dry pump.

I don't let mine get that close but since I tow a lot I let it get down much closer and do a complete fill, taking almost 5 gallons.

Just seems to work better that way. You have plenty of warning with the count down.

 

Sorry, I meant in my case, where the DEF tank is full right now, and still counting down. At any rate, it doesnt sound like it will strand me.

 

It won't strand you and since you know it still has fluid a dry pump is not a concern either.


I would just let it get down and see if it will fix itself.


Other option of course is to take it under warranty and have them reset the thing.

 

This is probably the best course of action.

Let the dealer reset it, and from now on fill the DEF when the truck tells you too (under 500 miles to empty). Make sure you fill it completely, it'll take close to 5 gallons.

 

This is infact what I just did. Small town, caught them at the right time, they wheeled it right in, and took a look. They had it an hour, said they reset everything, and topped off the def tank (again). On the way to the dealer, it in fact did reset itself, as others said it would. I called the dealer, and told them that, and they said to bring it in anyway.

I'm not real worried, its just different behavior than what i had with my 2011.

 

I had the exact same problem as you about a month ago; I got the 500 mile countdown message, yet I knew there was plenty of DEF in the tank since I put in 2.5 gallons when I notice it is below half. Bought a new jug, went to pour it in, and made a big mess when I overfilled the tank. The message and countdown continued for the next few drive cycles, then mysteriously went away.

Got another "below half" notification on my vacation a couple weeks ago, bought a 2.5 gallon jug to fill it, and overflowed it again. From now on I'm going to drive it awhile on the "below half" notification before adding another jug.

Ford really should add a true gauge and float on the '17's for the DEF tank, but I doubt they will.