Javi's Rules for DEF Usage..
Senior User
Joined: Feb 2015
Posts: 268
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Now for the $.50 question:
Can someone siphon out 3 gallons or so to get the level down below 1/2 tank and reset the countdown timer once it goes into the loop, that usually requires a trip to the dealer, and avoid a trip to the dealer?
Can someone siphon out 3 gallons or so to get the level down below 1/2 tank and reset the countdown timer once it goes into the loop, that usually requires a trip to the dealer, and avoid a trip to the dealer?
Logistics Pro
Joined: Jan 2013
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And then you grew up...so how is Ethyl these days?
Senior User
Joined: May 2015
Posts: 183
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From: coldwater Michigan
information center
I have an XLT . It's like an idiot light.
You push the setup button once and it'll tell you to push reset once to check the system.
Then you will see... OIL LEVEL OK or not and then it'll say DEF LEVEL either OK or level under half full.
Ford recommends filling it soon when you see this message.
Old DEF starts to break down and if you have a jug of DEF that you didn't use all the way in the back of your truck leave it there and get another jug .
After a while look at the old jug and you will see it have contamination in it.
You can get DEF at tractor supply stores. It's usually $8.99 a gallon plus tax
Senior User
Joined: Jan 2013
Posts: 151
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From: Spring Hill, SC
My truck typically will take 2.5 gallons of DEF when I change oil. Oil changes are by the warning light at around 7500 miles or so. Never seen the DEF light say anything other than DEF level OK.
Laughing Gas
Joined: Jul 2010
Posts: 1,155
Likes: 31
From: Idaho
No Worries
In general I follow if have full I find def when I go to Wal-Mart. If I go on a long trip I fill it. I have never made it to a count down on miles.
I have pulled heavy for thousands of miles and have not hit the count down.
Some people have trouble with the sensor.
I use my truck Dailey so the def is not spoiling.
Lots of trucks and some will have issues. Don't worry too much about when to fill def.
I have pulled heavy for thousands of miles and have not hit the count down.
Some people have trouble with the sensor.
I use my truck Dailey so the def is not spoiling.
Lots of trucks and some will have issues. Don't worry too much about when to fill def.
Laughing Gas
Joined: Apr 2007
Posts: 1,238
Likes: 2
From: North Port, Florida
Sorry, but this is terrible advice and can actually cause trips to the dealer.
Continually topping off the DEF will in some cases lead to the miles to empty continuing to count down regardless of the DEF tank being full. Then you have to take a trip to the nearest Ford dealer to have it reset
Follow what the owner's manual states, and watch the messages on the dash for proper DEF usage.
Continually topping off the DEF will in some cases lead to the miles to empty continuing to count down regardless of the DEF tank being full. Then you have to take a trip to the nearest Ford dealer to have it reset
Follow what the owner's manual states, and watch the messages on the dash for proper DEF usage.
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New User
Joined: Jun 2014
Posts: 10
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Army. I'm new to diesel too (just 2 weeks). I, like you, am retired and need to pee every 50-60 miles. How about we just pee into the def tank, add distilled water, and head down the road. Certainly be cheaper than buying the def.
Post Fiend
Joined: Jun 2004
Posts: 9,293
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From: Parker, CO
This thread is over a year old, and there were some arguments that happened.
It's not often I say "I told you so"..... but here it is....
Last week Ford came out with a service message, and basically stated that the DEF system needs to see a refill event in order to reset the DTE (Distance To Empty). Here is the exact message, please note the part in bold/underline/italics:
In short, follow the owner's manual and fill up the DEF tank when the truck tells you to. Continuing to top off the system can (and in many cases has done so) cause the system to throw the DTE warning even with a full tank. The system must see a refill event in order to reset, and the ONLY way it can see this is if the tank is allowed to run low.
It's not often I say "I told you so"..... but here it is....
Last week Ford came out with a service message, and basically stated that the DEF system needs to see a refill event in order to reset the DTE (Distance To Empty). Here is the exact message, please note the part in bold/underline/italics:
SSM 46093 - 2011-2016 F-Super Duty/2015-2017 Transit - Diesel - Diesel Exhaust Fluid (DEF) Warning Information
Diesel customers may inquire about a Distance to Empty (DTE) warning message for the DEF system. It may be necessary to add up to 2.5 gallons of DEF for the system to detect a refill event and clear the DTE warning messages, however it is recommended to fill the tank to capacity, which may take up to 5 gallons. Driving conditions that increase fuel consumption will increase DEF consumption and will require additional fills between oil change intervals. If the DTE message is displayed and no Diagnostic Trouble Codes (DTCs) are present, read the Reduct_TNK_LV PID with the Integrated Diagnostic System (IDS). If it reads less than 100%, DEF must be added. If the message doesn’t clear after the PID reads 100%, runthe IDS SCR System Refill Activation routine.
APPLICABLE VEHICLES
2011 - 2016 TRUCK: FA P473 SUPER DUTY
2015 - 2017 TRUCK: TH TRANSIT V363 FNA
Diesel customers may inquire about a Distance to Empty (DTE) warning message for the DEF system. It may be necessary to add up to 2.5 gallons of DEF for the system to detect a refill event and clear the DTE warning messages, however it is recommended to fill the tank to capacity, which may take up to 5 gallons. Driving conditions that increase fuel consumption will increase DEF consumption and will require additional fills between oil change intervals. If the DTE message is displayed and no Diagnostic Trouble Codes (DTCs) are present, read the Reduct_TNK_LV PID with the Integrated Diagnostic System (IDS). If it reads less than 100%, DEF must be added. If the message doesn’t clear after the PID reads 100%, runthe IDS SCR System Refill Activation routine.
APPLICABLE VEHICLES
2011 - 2016 TRUCK: FA P473 SUPER DUTY
2015 - 2017 TRUCK: TH TRANSIT V363 FNA
Super Moderator
Joined: Aug 2008
Posts: 37,384
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From: Frederick, MD
X2 above. There really is no concern of running out either. You get plenty of warnings and def is everywhere.
I take 5 gals with me when traveling far as a convenience factor. If concerned then anyone can do the same.
I take 5 gals with me when traveling far as a convenience factor. If concerned then anyone can do the same.
Senior User
Joined: May 2015
Posts: 183
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From: coldwater Michigan
DEF
No heavy jug to contend with and it's a lot cheaper....
I used 1 gallon of ammonia to 2 gallons of distilled water......repairs for this idea only cost me $9648.00
Take my advice and go to where big trucks put theirs in.. Usually $2.75 a gallon👍
New User
Joined: May 2019
Posts: 5
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From: Medford oregon
let it run down
def is water based with a fertilizer type substance in it. i'm shure you've noticed that the fill spout has white crystallized stuff on it. i've heard that it will eventually do that in the tank when it gets old. if you ley it ru low then you will always have mostly fresh def when you fill
Senior User
Joined: Aug 2015
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Just last week I was on the way home from a month long RV trip. Something seemed different in my DEF messaging this time. Not sure just why but here goes. In the past my truck would give me a 500 mi warning, then later on a 200 mi warning ( this is where I would usually plan to fill it). After the 200 mi warning it would begin a countdown every 10 miles. Now something different happens and last week I did get the 500 mi warning as is usual but after that it began the countdown and it showed up on the dash every 5 minutes or so. I waited until I got home and filled it and it was pretty much right at 5000 miles since I filled it last. This is the first time I've ever let it get that low but I try to always let it get to the 200 mi warning before filling. This will tell me that the level sensors and warnings are all working. I suspect these changes may come about after a dealer re-flashes the computer but it's been awhile since it was last at the dealer.
That's my story and I'm sticking to it. Yours may differ.
Roger from NJ
That's my story and I'm sticking to it. Yours may differ.
Roger from NJ