"Poor DEF QUality Detected" now what

quillcom

Well-Known Member
Just got this message today along with the constant flashing exhaust symbol.

Got a 100 mile jaunt up yo Fondy, WI

Stopped at a rest stop 15 away from drop ask other truckers what their experience was when this happened.

They said they ignored it but days later they were derated to 15mph
or less.

Called dispatch they said you should be ok it may be just a sensor problem.

Told them I have never seen this truck do this before.

I'm going to have them look at it tonight.

What are your expos on it?
 

quillcom

Well-Known Member
EF problems and DPF regens aren't connected... you do know that
All I know is that it asked for regent so I'm giving it. It did not ask for it prior to this prob.

Now I got 90min before 5mph derate.

Update 75min
 
Last edited:

quillcom

Well-Known Member
So

Word is we have to watch where we get are def from. Yes I basically was sucking it from one place only.
Looks like I wont be pulling def from there anymore.

Some say you should not get def from fuel islands at all but we should be buying it.

@ironpony I knew that regens help to get rid of the soot from the filters or wherever,
does not having bad def liken the possibility of extra soot? I'm asking
 

ironpony

Professional Pot-Stirrer
Supporter
I knew that regens help to get rid of the soot from the filters or wherever,
does not having bad def liken the possibility of extra soot? I'm asking
DEF is injected in a catalytic converter after the DPF to diminish formation of NOX - it doesn't add to the backpressure on the engine exhaust like soot contamination in the DPF. AFAIK, we wouldn't even know it was there except for all the extra software and hardware added after Navistar/International started whining about everyone else's approach to NOX suppression after they realized that the MaxxForce engine wouldn't come close to meeting EPA 2010 targets.
 

quillcom

Well-Known Member
DEF problems and DPF regens aren't connected... you do know that?
First, need to know the basics about diesel exhaust fluid? Read our 10 FAQs and answers about DEF.

When Good DEF Goes Bad – What Happens
Bad DEF can lead to a host of equipment issues, including:
-Increased consumption by equipment
-Loss of DEF effectiveness
-Issues with equipment, including engine de-rating or shut-down
-Potential damage to components, including DEF dosing pump and diesel particulate filter
-Malfunctions with the machine’s SCR system

So it appears you were right on the soot issue, but saying they were not connected is
a bit of a stretch. Did I not just learn they were connected today when it asked for a regen.

Thanks for your help.

What Happens When Good Diesel Exhaust Fluid Goes Bad
 

SueAnn

Well-Known Member
Supporter
First, need to know the basics about diesel exhaust fluid? Read our 10 FAQs and answers about DEF.

When Good DEF Goes Bad – What Happens
Bad DEF can lead to a host of equipment issues, including:
-Increased consumption by equipment
-Loss of DEF effectiveness
-Issues with equipment, including engine de-rating or shut-down
-Potential damage to components, including DEF dosing pump and diesel particulate filter
-Malfunctions with the machine’s SCR system

So it appears you were right on the soot issue, but saying they were not connected is
a bit of a stretch. Did I not just learn they were connected today when it asked for a regen.

Thanks for your help.

What Happens When Good Diesel Exhaust Fluid Goes Bad
I've had issues with DEF and now I know why. Thanks for posting that. It was really helpful.
 

ironpony

Professional Pot-Stirrer
Supporter
First, need to know the basics about diesel exhaust fluid? Read our 10 FAQs and answers about DEF.

When Good DEF Goes Bad – What Happens
Bad DEF can lead to a host of equipment issues, including:
-Increased consumption by equipment
-Loss of DEF effectiveness
-Issues with equipment, including engine de-rating or shut-down
-Potential damage to components, including DEF dosing pump and diesel particulate filter
-Malfunctions with the machine’s SCR system

So it appears you were right on the soot issue, but saying they were not connected is
a bit of a stretch. Did I not just learn they were connected today when it asked for a regen.

Thanks for your help.

What Happens When Good Diesel Exhaust Fluid Goes Bad
Dude, there's no connection between the SCR/DEF and your DPF. They're unrelated emissions system.

Interesting article though. If you're concerned about DEF quality, it would be an idea to carry a small, empty glass jar to dispense a sample of pump DEF to inspect before filling your tank.
 

r3gulator3

FLATBED GANGSTER
Supporter
It’s not always about the DEF you bought. There are several things that can cause this, bad sensor, a coolant leak into the tank, yielded or corroded terminals at the plug on the top of the def tank. Bad wiring, crystallized def in the decomp tube or One Box depending on if Cummins or Detroit, a leaking def injector, doing a regen won’t cure it.
 

r3gulator3

FLATBED GANGSTER
Supporter
does not having bad def liken the possibility of extra soot? I'm asking
Def is injected into the decomposition Tube where it passes thru a mixer plate and into the SCR Catalyst. This all happens down stream from the DPF, initially if you have a Freightliner product there is a def quality sensor in the Def Tank on 2013 and newer models and the wiring to it is common to corrode. Also the inlet and out let Nox sensors take readings and can throw this code in a truck without the quality sensor and that can be caused by the list of other problems I gave, not necessarily buying bad def but, it can be contaminated by other things. There is a metal coolant tube that runs through the tank to keep the def fluid in winter. They are prone to cracking. Leaking def injector causing def to crystallize on the mixer plate is the third most common.
 
Top