I got the low DEF fluid message today. 800km to empty (500 miles). I checked early in the day and message said DEF fluid level was O.K. I never got the message exhaust fluid 1/2 full. I had a jug at home so when I arrived home I filled the tank. I had a 2.5 gallon jug. I assumed it would take the entire jug. It would only take 2/3. It would appear I have a false low DEF message. This happened shortly after purchasing the truck but then it seemed to correct itself until now.
I now have 40,000 km's (25,000 miles) on the truck. I have an appointment at my dealer for an oil change Monday. I will bring it to their attention.
Anyone else experience this problem?

 

It did the same thing to me. One time.

Drove the truck and trailer several hundred miles. Parked trailer and unhitched. After awhile, restarted the truck. 500 mile warning came on. Little while later, restarted the truck and went into system and it said DEF "OK".

Just to be sure, put in DEF. Took about 2 gallons.

No issues since. This happened about 2 months ago. 8800 miles on the truck.

I wonder if the "miles to go" is using a corrupt version of how many MPG you are getting versus a physical read on the volume in the tank. Thus it is calculating poorly (calculating that we are using so much, so quickly) versus an incorrect reading.

 

Unfortunately, I have heard of several that have had that problem. Varying reasons - from bad DEF pumps to unknown glitches that a computer reset fixes.

It is one of the reasons I try to keep mine topped off as much as I can. I had an early 2011 that took along time to reset from the 1/2 full message - even though it was filled up so full DEF would spill out if you tried to add anymore.

SInce you have a 2013 - I haven't heard of any software updates to help with that (there was one early on). Let us know what the dealer says.

 

I had this issue on my current truck 2013. The def was filled from new at dealer. I made it to around 3500 km and it went from showing OK to 800 km to empty. I had it to the dealer complaining it was only working on half a tank. They were skeptical at the time so they refilled it and I kept a log book. Sure enough around the same mileage it went from ok to 800 to empty. It was working on the basis of half a tank. With the log book proof they replaced the sending unit and it has been good since.

 

Thanks for the replies. The first time it happened was on a long trip out west. I never got the 1/2 full warning then I got 500 miles to empty. I filled the tank and the message cleared. This happened May of last year. It has been working O.K. since. Every tank I get the 1/2 full message then add DEF. More than half my mileage has been towing a 5th wheel.
I will call the dealer today.

 

Yes, this happened to me. It's a long story, but the short version is that I had the truck in the shop for a TSB and soon after I left it threw a low DEF pump pressure code and a few miles later I got the 500 miles message.

I filled the tank with DEF and the 500 mile message went away. So, I took the truck in to have the dealership check it and they found that the DEF was contaminated.

Don't want to highjack your thread so I won't go into all of the events/issues, but I would say that if you filled it with DEF, 500 mile message went away, correct DEF level was restored and you did not get a code it was probably a glitch in the software, etc.

 

You're taking a step in the right direction by contacting your dealership about this, grampscamper. Were you able to speak with them? I'll keep an eye out for an update.

Additionally, please send me a private message with your full name, VIN, best daytime contact number, and dealership information; I'll loop in a regional customer service manager for further assistance.

Hope to hear from you soon!

Brittany

 

Thanks Brittany, message sent. I'll keep you posted.
I will say that my dealer has provided me with outstanding service.

 

My truck did the same thing on the first 2800 miles. Went straight from "OK" to 500 miles to empty. Filled DEF tank with 2.8 gallons. At 5600 miles went from "OK" to less than half full as it should. Filled back up and it goes the OK again. Thought it was strange.

 

Sounds about the same as mine. It has been O.K. until the other day. I have an appointment booked for Monday. I didn't worry about it the first time it happened but now I should have it checked.
I'll keep you posted. Thanks for the reply.

 

Never do this. It even tells you in the owner's manual not to do this.

The first level indicator is at half full. So if you're constantly topping off the DEF tank, the computer never reads the proper level. Eventually it will just start counting down based on mileage, regardless of the fact that the tank is still above half full.

Also never overfill the tank. You're asking for more problems there.

 

Agreed! From experience......

 

run it down till you get about 200 miles to empty. Then fill completely.


Use the ford fill spout. It will shut off when full. It will not spill and allows for proper expansion if needed.

 

I'm trying to get a better understanding of how this works. I assumed warnings were based on the level of tank only and the computer countdown started at 500 miles to empty. I decided to get the manual out last night and read about filling the DEF. It said no action is required until 500 miles (800 km) to empty. It looks like it is designed to go from oil change to oil change. I know when I tow our 5th wheel this isn't possible. How does the countdown to empty start? Does it start when oil is set to new, mileage, level of the tank or a combination? I assumed when you topped it off at 1/2 full it would reset to full and restart the counter.
My dealer normally fills it when I get an oil change. I have topped it off since the last oil change to use up the remainder of the jug. The first time it happened I topped off the tank because we were taking a long trip out west. Pocket, it looks like I may have caused this problem. I will see what my dealer has to say tomorrow.
Can someone please explain exactly how it works so I have a better understanding. If necessary I will carry a spare jug when we travel and not fill it until I get the message 500 miles to empty.
Thanks for the replies.

 

It is suppose to be enough to go between oil changes. It is not when towing heavy. It goes just about 5K when towing.


I add def when it is needed, not with the oil change.


You should get a under 1/2 warning and then when you get the count down. 2013-present only has the 500 mile to empty then I think a 200 miles and then it counts down from there.


I'd recommend not filling it till you get down to 200 miles then do a complete fillup.


I think keeps it from being confused.