I have a 2011 diesel F-250 King Ranch. It has all the bells and whistles and is perhaps my favorite vehicle I have ever run. It's fantastic, and I have had absolutely 0 problems with it. I got a very early model, purchased around April 27. I'm pretty sure it was the first one on the road in NJ, and I still haven't seen any others...

Around 4000 miles I started getting DEF level alerts, starting with 800 miles of capacity left. When it got to around 200 miles left, at around 4700 miles on the odo, I bought a 2.5g jug of DEF from my local Ford dealer and poured it all into the tank. The warning message first showed the same 200 miles left, then 500 miles left, then 800 miles left, but never got above that, and never cleared.

At this point, the range remaining on the DEF warning started counting down from 800. I now have around 5100 miles, and the DEF warning is saying 500 miles left.

So, it appears to me that either a) my DEF range sensor never quite got updated, or b) I needed to put in a lot more than 2.5g of fluid.

Is there a way to reset the DEF light, or do I really need to put in a lot more DEF?

Thanks, Dave

 

I haven't had to do this yet but looking at the manual again I think you didn't add enough to get rid of the messages. It's a 5 gal. tank. The manual says if the message is "less than half full" add a maximum of 2 gal. If you were getting the 200 mi. message I think you were pretty low.

 

Also consider the rate at which you may use the fluid. Light driving will yield long between fillups.

Towing will increase the burn rate.

 

Right, the DEF is used only when the exhaust temperatures are high enough to produce NOx. If the engine is barely warm and you're in stop and go traffic, the exhaust temps never get high enough to produce NOx and therefore no DEF is injected. When you're pulling a load over mountain passes (while passing many Dodges btw), the system injects DEF to break up the NOx. Ford said your DEF tank can be consumed in as little as 2,500 miles if you're really running hot for extended periods. It's the Tow Masters that go through DEF rapidly. Grocery-getters don't use much.

 

Just wanted to add that you get the 1st DEF fillup free from your dealer plus a $50 off 1st oil change coupon... Take advantage.

 

Okay sorry, but I've been dieing to use that one.
It's actually time for me to read mine again, for the third time. It's my first diesel so a lot to learn.

Welcome to THE club of 11!!

 

Unless I am missing something I did read it. I am agreeing with his option b) that he needed to add more. The manual doesn't talk about partially filling the tank it describes filling it full. He asked why he was still getting the messages.....simple....not enough DEF. What did I miss? Scratch the 2 gal.......the only point was that he is still less than half full.

 

Yes, just didn't put enough DEF into the tank. Put another 2g into the tank and I've been all set. I'd say my truck is more of a grocery getter so far, although I'm leaving on a 5K+ mile heavy towing race trip next week, so we'll see what happens with DEF consumption and MPG.

 

I just filled mine today. I ran it down to a range of 348 miles. Bought 2 2.5 gal jugs of Peak Blue DEF at a Pilot ($29.00) and probably put in 4.5 gallons. I just have a little left over that I will top off with soon.

By the way, the Blue DEF comes with spouts that you screw on the jug but when the tank is full it just overflows everywhere. Other brands have a better spout that stops the fill when the tank is full without anything being spilled.

My truck has 6700 miles on it, dealer topped mine off at 1250, I think when I took delivery at 220 miles it was only half full.

 

When it 'overflows everywhere' does it get outside of the fill cavity and onto the paint? Just curious. My son's '11 GMC has a tray around the filler neck that directs any spillage to the ground plus (or actually a minus) the fill point is under the hood.

 

spill tray in fueling well

 

For my own clarity, do you know: Is the DEF injection rate strictly a function of EGT? Or are other factors considered by the ECU in controlling injection rate?

 

Your DEF miles to empty problem should be cured by the upgraded hp flash. Among several other minor issues, this is covered under that.