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DEF systems

Vetech63

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Aug 10, 2016
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Oklahoma
I recently quoted a new Pettibone 204 Tier 4 pipe handler to a customer. I was told by Pettibone that the DEF system CANNOT be run out of fluid...…………...if so, the Cummins people have to come out and plug in their computer to get the machine to run again. Does this make sense to anyone? What is aggravating me is the new machine has a super small DEF tank, and they are telling me it will need topped off every 1.5-2 tank fill ups. I'm not that familiar with the DEF systems on most other equipment, but does this seem normal? I have a new 2018 Dodge truck with the Cummins and no one said anything of the sort...……..although Im getting 5-7 tanks of diesel per 5 gallon fill up on DEF.
 

farmerlund

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A lot of our farm machines have to be filled every 2-3 tank fulls of diesel. Some of it varies on how hard you work the engine. The harder its worked seams like the less DEF is used. once you are used to filling them its not that bad to remember. reliability and throwing codes is a whole different story. LOL. Yep its stupid.
 

funwithfuel

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Will county Illinois
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If the system detects empty for a prolonged period, it derates. Once you enter second level derate, it recognizes that as "tampering"
Which must be recommisioned by a dealer tech . Thank you EPA.
Yes, they are supposed to spec tanks to last at least one and a half tanks of fuel or a solid days work.
That's the way the Cummins rep explained it to me.
 

Junkyard

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Sounds close to right. Your dodge will only go so far empty on DEF before it derates to almost nothing like 15 mph.

As far as the Perttibone and Cummins I would think it would warn you before it went crazy. Cat told us on the newest rig you have two chances to ignore a regen or run out of DEF before it takes ET to bring it back to normal. All a pain if you ask me....
 

hvy 1ton

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mg2361

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Pennsylvania
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This is out of a Deere manual on SCR derates.

The DEF and SCR systems on Final Tier 4 engines are required to reduce NOx emissions generated by the engine. When certain components of these systems malfunction, the NOx emissions increase and the engine is out of emissions compliance. To keep the engine in compliance with emissions regulations, a separate derate schedule is used for the DEF/SCR system malfunctions. There are certain faults that can occur where the ECU cannot determine if the system is operating properly and the ECU shuts down the DEF dosing system. When this happens a warning is displayed and an internal counter is started. The engine will operate normally without the DEF dosing system operating, but the NOx emissions will be out of compliance. Once the internal counter reaches 4 hours, a derate with a 50% torque decrease and engine speed reduced to low idle will be implemented over a 10 minute time period. This will, in effect, disable the engine from performing as needed. Once the DTC’s that caused the counter to start are repaired, the counter will stop, and if the derate was implemented, the derate will be removed. However, if another DTC is set that shutdowns the DEF dosing system, the counter will restart at the point it was at when the previous DTC was repaired. To reset the internal counter, the engine must operator for 40 hours without a DTC that shuts down the DEF dosing system. If a DTC is set during this 40 hours, the counter will start from the previous count.
 

63 caveman

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western Pa.
They may have sized the tank small because tier 4 equipment that sits for longer periods of time is going to have problems with the after treatment system because the self life of DEF is much shorter than fuel. I hope someone comes up with a better after treatment system, there are just to many problems with this currant system.
 

Vetech63

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Oklahoma
So...….with all the brilliant minds in the world, that cured Polio...……….that sent man to the moon, ……..that created the computer, cell phones, internet...…………..THIS SYSTEM IS THE BEST THEY COULD COME UP WITH?! JESUSSSSSSSSSSSSSS :confused: There has GOT to be a better way.
 

funwithfuel

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When the engineers write it all out on the whiteboard it looks like a chemical equation for an advanced placement science test The bottom line is thhe SCR stand alone systems seem to operate more efficiently and more reliably then the tier 4 interim systems did.. Most have done away with burners and DPF
The bigger picture is we need to look forward to what tier 5 or stage 5 is going to bring us it's been postponed thanks to the trump administration thank you Mr. Trump but it's still coming down-the-line eventually .
 

Junkyard

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I’ll say from my experience with trucks that DPF and DEF is better than DPF alone. Considerably believe it or not. If they’ll keep the thing from needless idling it will make a HUGE difference. I’d go as far as to see about having the ECM programmed to kill it after so many minutes of idle time.
 

crane operator

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Mar 27, 2009
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sw missouri
I don't like the whole "anti-idle". I realize its the best way to deal with the DPF and DEF issues, but for my primary application- in the cranes, we do a ton of idling. We're working, swing a piece over, and sit there while they connect it. Then rev it back up, swing over and grab another piece. Might be minutes between picks, might be hours.

But you can't hardly shut the stupid crane down everytime. Then when you restart, you have to go through the whole set up computer/LMI screen, and frankly, if I've got a bunch of stick out on a job, I don't like to shut them off. It may not restart. Who want's to sit there with 188' of boom out over top of something, and if you shut it down, its 3 minutes until you can get back moving again, if it starts. Its a question without a lot of answers. Charging by the hour, the customer wants that crane moving when its time to go.

I've recently run into a lot of guys in the trucking game that have totally given up on the new trucks, and have gone the "glider" route. But they are all worried, that its a short term solution with the gov't limiting production numbers.
 

92U 3406

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This is out of a Deere manual on SCR derates.

The DEF and SCR systems on Final Tier 4 engines are required to reduce NOx emissions generated by the engine. When certain components of these systems malfunction, the NOx emissions increase and the engine is out of emissions compliance. To keep the engine in compliance with emissions regulations, a separate derate schedule is used for the DEF/SCR system malfunctions. There are certain faults that can occur where the ECU cannot determine if the system is operating properly and the ECU shuts down the DEF dosing system. When this happens a warning is displayed and an internal counter is started. The engine will operate normally without the DEF dosing system operating, but the NOx emissions will be out of compliance. Once the internal counter reaches 4 hours, a derate with a 50% torque decrease and engine speed reduced to low idle will be implemented over a 10 minute time period. This will, in effect, disable the engine from performing as needed. Once the DTC’s that caused the counter to start are repaired, the counter will stop, and if the derate was implemented, the derate will be removed. However, if another DTC is set that shutdowns the DEF dosing system, the counter will restart at the point it was at when the previous DTC was repaired. To reset the internal counter, the engine must operator for 40 hours without a DTC that shuts down the DEF dosing system. If a DTC is set during this 40 hours, the counter will start from the previous count.

That must be the EPA regulations as CAT is pretty much identical to that as well with counter and derates.
 

funwithfuel

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The way I understand it, the EPA dictates what and how. Its up to the engine mfr to fit in those parameters, submit it for approval and wait. But we should all feel better knowing they're here to help. o_O
Back to original point. I believe most tanks are produced by 2 or 3 companies. Would it be possible to spec or demand a larger tank. The only downsides would be the ability to thaw a frozen tank in the winter and wasting a tank that sat too long.
 

StanRUS

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Cal
I’d go as far as to see about having the ECM programmed to kill it after so many minutes of idle time.

Most mid-range trucks are programmed to shut down engine after XXX minutes idle time. Adjustable duration via the ECM.
 

heymccall

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Feb 19, 2007
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White Oak, Pa
Seeing as my service truck and my wet line lowboy trucks are Tier IV final, and do a lot of idling (lowboy is around 30%, and my service truck is around 50%), the excessive idling solution is to raise the RPMs, when encountering prolonged idle periods. My service truck does this automatically, raising the RPMs to 1050 for 5 minutes, on 15 minute intervals.
90k miles on the service truck, and one time, the DEF doser nozzle needed cleaned, and, one time, the EGR valve passage needed cleaned. The only other check engine light events were for a turbo actuator electrical, and a failed exhaust manifold gssket.
 

92U 3406

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The way I understand it, the EPA dictates what and how. Its up to the engine mfr to fit in those parameters, submit it for approval and wait. But we should all feel better knowing they're here to help. o_O
Back to original point. I believe most tanks are produced by 2 or 3 companies. Would it be possible to spec or demand a larger tank. The only downsides would be the ability to thaw a frozen tank in the winter and wasting a tank that sat too long.

Biggest issue we have is with telehandlers. They all have direct drive fans and they never really get worked hard. When -28C and colder hits, it takes too long to get the DEF thawed so then it throws inducement codes. I think the biggest stumbling block is operators. They do not know how to run this stuff correctly. These emission systems need heat. You can't make heat with 80% idle time and 20% light work.

I am so glad I'm getting out of the rental industry just as we're replacing our old gensets with tier 4 ones. We have had nothing but wet stacking issues with our older units because everybody rents gens that are much too large. I kid you guys not we had a customer run a 100KW gen all winter powering only a single 1000 watt light. Then they complain that the thing is a POS because it freezes the crankcase vent twice a week and pukes out all the oil o_O
 
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