I just got my first DEF 800 mile warning, but with only 3200 miles on the truck. I had seen other posts where people were getting 5000-7500, so I was a little disappointed by my range. I know it's based on driving habits, but I go pretty easy on it (averaged over 18 mpg since new) and have only towed twice. I also haven't gotten the oil change alert yet, so I don't think it's usage related. Maybe it wasn't topped off at the factory or dealership?

As far as the warning in the message center, all I got was the 800 mile warning. I think others have said they were told when they were below half full? I checked in the information center before the 800 mile warning and it just said exhaust fluid OK. What are others seeing?

 

Mine says DEF under half full right now with only 2600 miles on it. Haven't got the 800 mile message yet though. Mine goes in a week from Monday for first oil change. Taking a 2k mile trip in July and didn't want to wait till I came back. Free first oil change and DEF refill.

 

Are you seeing that in the information center? When I checked mine, it just said exhaust fluid OK. No indication of level.

My regens have also picked up significantly. When I first got the truck, I was getting a regen every 250-300 miles. Now they are down to 100. While that is technically within spec, I hate to see it change so much over a short period of time. Only thing I can think of is that the DPF gets a little buildup in it over time and needs to regen more often.

 

Interesting...you got an 800 mile warning but now it says the level is okay?

I've read some similar cases where something went wonky with the sensor and it gave some erroneous warnings. When your truck says the level is "OK" that means that you are above half full and have much more than 800 miles remaining.

My truck drank a total of around 8 gallons of DEF in the 10,000 miles I had it. Like you I didn't put much hard use on it, it was mostly rural highway driving.

It's also possible that you didn't have a full tank to begin with, but if you're still showing "OK" I think you most likely got an erroneous warning.

 

No. I always play around in the information center just looking at everything. 2 days ago, it said exhaust fluid OK. Then last night I got the 800 mile warning (no half full indication at all). Now it says something like 765 miles left. I'm about to go fill it now and will let you know what happens and how much it drinks.

 

My first 5 gallons lasted 6500 miles until the 800 mile warning last October/ November time frame. Filled the tanks with 5 gallons on DEF now have 17,700 something and have not filled it since. Last time I checked the fluid reading on the dash it said below half.

I think the DEF spent most of the winter frozen or in a slushy state and did not use any over the winter. But I am not going to complain truck runs fine.

I would say your tank did not get filled all the way from the factory or at the dealership when you picked it up. I believe there have been a few that were that way. I have also heard of a few people getting new DEF tanks and pumps for faulty readings and such.

I think you are on the right track fill the tank then see what happens, if it still acts up then you know you need to go to the dealer. Good luck

 

I'm pretty sure they don't fill the DEF tank all the way full at the factory.

I got the 1/2 Full indication at 2650 miles at which time I added 2 gallons. The next 1/2 Full indication came at 6165 miles which results in 3515 mi / 2gal.

So I use 1750 mpg as an estimate of how much it uses.

Next fill was my freebie. They put in 3.65 gal at 8900 mile. That works out to right around 1750 mpg again.

Going by all that I worked out that there was 4.25 gal DEF added at the factory.

So I wouldn't worry that you are using more DEF than others because you don't know how much you started with.

But for the second part, there is no way it should have gone from OK to 800 miles warning in a couple of days. In my case, I'd expect 3500 miles+ after seeing 1/2 full and before seeing 800 mile warning. Something doesn't add up there. 800 miles means you are at something less than a gallon so you should have been seeing 1/2 Full indication for quite some time now.

 

OK, so I just went and added 2.5 gallons. Towards the end of the fill, I got a little overflow but it slowly drained into the tank. I think it could maybe take a little more, but I don't want to open up a new 2.5 gallon jug and only use a little. So now, the information center says the level is OK. Don't these tanks have a 5 gallon capacity? If so, why would it only take 2.5 gallons after giving me the 800 mile warning. I'm wondering if I have a sensor issue. I'll let it go one more cycle and see how many gallons it takes next time.

 

Do you get the 1/2 warning as a pop up like the 800 mile or cleaning exhaust filter message or do you only see it by drilling down and seeing it along side all the other stuff (oil, engine hours, etc)?

 

It's not a pop up. I have to go look in the info center and the only thing I've ever seen there is "Ok" or "Less Than Half".

Based on all the info you gave including how much it took to fill it up, you should have been seeing "Less Than Half" right around now and not 800 mile warning.

Something is not right about that. Since it is probably not an emergency and since if you take it in now, everything will look correct, I'd probably wait and see what happens in 3000 - 4000 miles from now. At that time it should indicate 1/2 Full.

If it goes straight to 800 mile warning again at that time, that's when I'd take it in to get looked at.

 

So I just went out to see how much more it would take. It backed up quickly, but would eventually drain in. I got another gallon or so in, but read in the manual about overfilling damage, so I don't want to push it any more. Not sure what damage can occur, but I'll just leave it as is with approx 3-4 gallons added and see what happens. So much for these spouts that are supposed to stop when full. I got several overflows, but then it took more after that. Not sure why. It's not like this is foaming diesel fuel.

 

I wish Ford would have put a real gauge on the DEF tank. I have a little over 3K now and I poured a gallon in the tank yesterday. I guess the best way is to pour 2.5 gallons in when you get the 800 mile message. I have not seen a DEF pump at a station yet...

 

I'm wondering if they made a change between Job 1 and Job 2 trucks and removed the half full warning for Job 2?

I have a Job 2 and never got a half full message anywhere, no pop-up and nothing on the vehicle information screen.

I did get a popup at 800 miles remaining and again every time I started the truck after that. Took it to a dealer and got the first fill up at 3174 miles (lots of heavy towing). It took 4.6 gallons and the service writer said it is a 5.5 gallon tank.

 

I have a Job 2 truck, 4/11/11 build date, and I have the less than half full indicator. I had to do that from the System Information screen to see it. It does not, or at least on mine, come up automatically. I scan that area a couple of times a week, simply still a newness factor for me, but I suspect I'll do it less often as the months go on.

I bought five gallons of DEF from Ford, put 2.5 gallons in without issue, and the message changed to the tank is full status. I put the other 2.5 gallons on the shelf and will wait until the message changes again before I try to put it in.

Reading the label, and advice from both the Ford diesel mechanic and parts manager, is that DEF is caustic and will harm your paint. I do not want to spill any I don't have to and risk causing paint and then rust issues.

 

I always run mine down to nearly empty and then I can easily fill with 5 gallons with no spills.

1/2 full message is in the truck "system check" menu.
800 m to empty is a pop up, and each time you start the truck it will pop up with your current m to e range.
At 100 m to e is when I think it warns you that speed will be limited to 55 mph when you reach 0 miles to e.

Sounds to me like your def system is working properly.