My 2012 F350 Lariat has 6100 miles on it now and on the way home tonight I got a "speed limited to 50 mph in 50 miles" message on the display. It states that there is a "diesel exhaust fluid system fault". The def was topped off about 2000 miles ago and the message center says that the fluid level is "ok". I am going to be on the phone with the dealer first thing in the morning. This is my personal/work truck and if I can't tow a trailer then I can't work. My guess would be a faulty sensor. Just curious if anyone else has ran into this and what the problem turned out to be. I have no doubts that the dealer will get this resolved quickly as they have been great about everything else. I also want to say that other than this, I am sure minor issue, this truck is awesome! I love everything about it.

Jeremy

 

my guess is low def level. the reason for the 50 mile warning.

 

I just filled it up 2000 miles ago with def and the display says that the def level is ok. It doesn't even say that it is less than half. I appreciate the feedback but I think it is something other than fluid level.

 

It wouldn't hurt to get a 2.5 gal jug and dump it in......

 

Definately worth a try for 12$. Just don't burn up part of your 50 miles, by running to Wal Mart in the truck, in case it is the sensor..

 

One of the many drive ability problems my truck experienced. The exact same scenario you experienced. I stopped the truck several times and tuned the engine off waited a few moments and restarted. The "speed"warning went out but the "repetitive" CEL stayed on. I think that was the first DEF pump replacement ( 3 DEF pumps as of now). Good luck!

 

At the dealership now......will update when I know more

 

Spent just over 2 hrs at the dealership. They followed Ford's guidelines for the problem which consisted of clearing the code, removing the def injector and running the pump to measure the amount of fluid coming out, drive the truck for 20 miles after injector was reinstalled and code was cleared.

Why do I have the feeling that this is not the last of this issue that I am going to see. No parts replaced just pretty much cleared the code. I just hope it doesn't happen again when I am a couple of hundred or more miles from home!

 

Was there something you had to reset when you topped it off 2,000 miles ago? I've only got 2,000 miles on mine...

 

No there is nothing to reset on the def to my knowledge. It is not like the oil change reminder. After you top it off it automatically senses the fluid level is

 

Yep, it senses the fluid level and resets. But if you get under 1/2 full you have to fill it high enough to get to the full sensor before it will reset. It's not like you fuel gauge that tracks exactly how much is in it.

 

I also had this happen this afternoon. After a few min of looking through the manual and playing with the display screen I headed for the dealership. Then after about 8km it went away. Hopefully it doesn't happen on my next days off when i head out of town.

 

Everyone ought to be prepared for some erratic DEF level messages during the winter. The slush, freeze, thaw cycles play havoc with the three position sensor. I remember several members complaining about that.

 

My truck indicated "speed limited to 50 mph in 50 miles" Two of my DEF pump failures in the summer time 90F. One in the spring about 50F. Maybe the next will be during the winter.

 

I can understand the freezing thing. But it was above freezing yesterday