Service DEF

[Robeffy]

Hi,
My CTD was parked all winter long, outside, Northern Canada. Temps got to -40C, which is basically also -40F.

On start up, I had a Service DEF system message, which went away.. Next time I started, same message.. The message is stored in the system.

The truck has no problem driving at any speed, I get no other messages.. Lots of DEF fluid in the tank... just over 3/4 full.

I haven't towed anything since I got the messages..

Questions ::

1) can I reset this message by myself?
2) is this a message from when the system was totally frozen at -40C, or is this a current message?

Thought anyone?

Thanks

 

[Robeffy]

It seems like I had better check the age of my DEF fluid, I bought a 2nd jug of it, so I can read up on that.

Also, looks like there is no way to reset it without a scan tool... I have a OBD 1 scan tool, bummer, shame its not OBD 2 ...

 

[GTyankee]

I read something on this site recently:

It read that you should never FILL your DEF Tank when winter conditions reach extreme temps, due to the DEF freezing, ice expansion & possible damage to the tank

 

[Robeffy]

Sad to say, I did fill it up just before I put it away.. Thanks for mentioning !


I have to wonder, what brainiac designed a system that uses a fluid that can freeze under normal conditions? We routinely get minus -30C weather, and -40C atleast a few times a year. This year we had nearly 2 weeks of -40C overnight, and highs of -25C some days.. Even with a heated tank, what about the lines where the fluid could gel up after the tank..

 

[GTyankee]

The system allows the vehicle to run for a period of time with the frozen DEF tank
There is a line that carries water from the radiator through the DEF tank, this turns the DEF to slush, from what i seem to recall.

I just found this, it explains everything

Diesel Exhaust Fluid FAQs

Does DEF Freeze? What is the freezing point? Is it safe to drive when your DEF is frozen? Learn about Diesel Exhaust Fluid with Mitchell 1’s FAQs.cccccccccc

mitchell1.com

 

[Robeffy]

Thank you.

I ordered a scan tool that lets you reset the error message, as a first step. If its an old message that is stuck in memory, I can erase it and forget about it. If the message returns, I will have to work on fixing it. Not too sure about removing the entire DEF system.. I know lots of people do it, I won't rule it out as an option. I am not interested in spending money on something that can mess up every winter, and I sure don't want to have to park my truck inside a heated garage ( and build a heated garage ). Next winter, a 1/4 full DEF tank at most.

 

[Robeffy]

Well, the scan tool shows a P207F error message.

I was able to erase it, no problem, with a Bosch OBD1100 tool, and the message just keeps on coming back whenever I turn the ignition key to the RUN position, ever before I start the truck.. The display says no Stored Error messages, and then displays the Service Def system message.

 

[GTyankee]

Most times, a repaired Code will erase itself after X amount of Ignition Cycles

So once the temperature rises & the DEF tank has thawed, a dozen or more start ups should clear the code

 

[Robeffy]

Very interesting! I am going to try that today..
Thanks very much for that info.
I started to look into buying a 2003 RAM, just to get away from all this DEF, DPF and CAT nonsense. I dont mind fixing up older trucks.. I still drive my 95 1500 everyday, after all. I want the CTD for towing my travel trailer.. Its overkill, but I would rather be overgeared than undergeared.

 

[Robeffy]

I started and stopped the truck a few times yesterday, and even drove it for 5km. Still getting the error message.. it snowed, but, I hope to get underneath finally today and see if there is anything obvious. Temp is right around freezing.. just finished off another job so I am going to dedicate some time to this one now.

 

[Robeffy]

Well, I tried to start and stop the truck more times, the temp has been in the low 40's ( Fahrenheit - lol ) so there is no way anything is frozen any more. Nothing changed, still had no message before the engine ran, and then the same message once the motor ran.
Eventually I said to heck with it, and drove it for atleast 1 hour. The next time it started, no message!
I have no real idea what happened.. it still has the old DEF fluid, its just not frozen up anymore..
100,150 km on it and its all working the way its supposed to.
Thanks all who helped me out, especially GTyankee..

 

[Beltsand]

Well, I tried to start and stop the truck more times, the temp has been in the low 40's ( Fahrenheit - lol ) so there is no way anything is frozen any more. Nothing changed, still had no message before the engine ran, and then the same message once the motor ran.
Eventually I said to heck with it, and drove it for atleast 1 hour. The next time it started, no message!
I have no real idea what happened.. it still has the old DEF fluid, its just not frozen up anymore..
100,150 km on it and its all working the way its supposed to.
Thanks all who helped me out, especially GTyankee..

Did the message come back? I am traveling in WY right now and got a service DEF message. It has not frozen. The DEF in the tank was put in about two weeks ago, and still at half a tank. Service department at the dealership said that message gives about 400 miles before it puts the truck in limp mode. No dealership within 200 miles can even read the code for three weeks. The truck is my only transportation, and it would need to pull a 5th wheel at the same time if I go any distance. Gotta love modern technology!

 

[Robeffy]

My problems seem to have gone away, I gather new fluid, more driving? I did try to erase the codes, maybe that had something to do with it? I have had many start / stop cycles, as was suggested could be needed.... Its a mystery, not sure what fixed it in the end. I am still not thrilled it happened at all, and think DEF and diesels are a bad idea