I asked this question in someone else's thread (click) (http://www.dieselplace.com/forum/showthread.php?t=355999) and want to start a separate thread on it.

An article states (click) (http://www.truckline.com/AdvIssues/Energy/Diesel%20Exhaust%20Fluid%20Documents/Diesel%20Exhaust%20Fluid%20%E2%80%93%20Frequently% 20Asked%20Questions%20%28May%202009%29.pdf) that DEF freezes below 12F. My question is, has anyone heard about cold weather operations for this? Your truck will go into limp mode if all is not well with the DEF. If you have a frozen chunk of DEF when you go to start your truck...what will happen?

Thus far the answer replied back is:
1. The tank is heated. (click)
(http://www.dieselplace.com/forum/showpost.php?p=3729888&postcount=22)
If the tank is heated, how fast does it thaw?
Does DEF freeze solid or just solidify into a slush?
Will a higher concentration of urea improve its freezing temp?
Are there additives to add to DEF to prevent it from freezing?
How reliable are the "tank heaters" and will you have to plug them in similar to the block heater?
Do you have to keep your DEF supply in the cab of the truck because if you keep it in your tool box it will freeze and you will not be able to poor it?

If anyone can come up with more questions or answers please chime in. Living in ND these are concerns I have about buying a new truck with DEF.

I couldn't find any info in the service manual but, I do not think you have anything to worry about. GM tests at some of the coldest places on earth. Every vehicle in North America goes through Cold Weather Durability at Kapaskusing, Ontario. In addition, they are overnight soaked at -40 C in cold boxes during powertrain development.

I couldn't find any info in the service manual but, I do not think you have anything to worry about. GM tests at some of the coldest places on earth. Every vehicle in North America goes through Cold Weather Durability at Kapaskusing, Ontario. In addition, they are overnight soaked at -40 C in cold boxes during powertrain development.

Now that you said that I know you'll get some snickers from those badass rugged more manly than everyone else in the world guys who live/work in the yukon territory, where it gets -150* and not -30* like in kapaskasing. :D :rolleyes:

ben

Now that you said that I know you'll get some snickers from those badass rugged more manly than everyone else in the world guys who live/work in the yukon territory, where it gets -150* and not -30* like in kapaskasing. :D :rolleyes:

ben

You think -150*F is cold? You ain't seen nothing. :D

To answer the original concern, it'll thaw quick enough. It's not like it needs DEF to start and move, it's only required every 700miles (up from every 400) during a "regen."

You think -150*F is cold? You ain't seen nothing. :D"

its t-shirt weather! ):h

Supposedly by the time the engine gets hot enough for DEF to be effective the DEF it will have thawed.

Does it really know the difference between urea and strait antifreeze? I doubt it.

I foresee these tanks freezing and cracking up.

The heavy truck makers have gotten a permit from the government that allow the truck to run without urea for a small amount of time while the tank thaws. I assume Gm is in the same boat.

Has anyone considered what would happen if you just put diesel in the urea tank?

Does it really know the difference between urea and strait antifreeze? I doubt it.

I foresee these tanks freezing and cracking up.

well thats why GM does their cold-weather durability testing at -40*c

arrrghh come on guys, for the one billionth time, its not like GM just found out yesterday that urea freezes at 12*, dont you think they would have tested the crap out of it at temps colder than that because probably 75% of the trucks they sell see temperatures that cold at least once in their lifetime?????????????????????????

And also, for the one HUNDRED billionth time, if you put anything but urea in the tank, YES the ECM will know, so stop thinking you can fake it out with anything else. Urea is cheap and will be available everywhere by the time they come out, so RELAX.

ben

well thats why GM does their cold-weather durability testing at -40*c

arrrghh come on guys, for the one billionth time, its not like GM just found out yesterday that urea freezes at 12*, dont you think they would have tested the crap out of it at temps colder than that because probably 75% of the trucks they sell see temperatures that cold at least once in their lifetime?????????????????????????

And also, for the one HUNDRED billionth time, if you put anything but urea in the tank, YES the ECM will know, so stop thinking you can fake it out with anything else. Urea is cheap and will be available everywhere by the time they come out, so RELAX.

ben


so you know for a fact what urea is made of?,if so tell us more//please

well thats why GM does their cold-weather durability testing at -40*c

arrrghh come on guys, for the one billionth time, its not like GM just found out yesterday that urea freezes at 12*, dont you think they would have tested the crap out of it at temps colder than that because probably 75% of the trucks they sell see temperatures that cold at least once in their lifetime?????????????????????????

And also, for the one HUNDRED billionth time, if you put anything but urea in the tank, YES the ECM will know, so stop thinking you can fake it out with anything else. Urea is cheap and will be available everywhere by the time they come out, so RELAX.

ben

I wasn't blessed with intelligence like yourself so please type slower for me. This is the second thread (click) (http://www.dieselplace.com/forum/showpost.php?p=3731674&postcount=27) that you have posted this same comment...yet you haven't explained much on how it works. It must bother you there or those that do not know how the DEF/Urea system works in cold weather.
Like the above post says, please explain how the system works and how GM designed it to work in cold weather like my original question asks.

well thats why GM does their cold-weather durability testing at -40*c

arrrghh come on guys, for the one billionth time, its not like GM just found out yesterday that urea freezes at 12*, dont you think they would have tested the crap out of it at temps colder than that because probably 75% of the trucks they sell see temperatures that cold at least once in their lifetime?????????????????????????

And also, for the one HUNDRED billionth time, if you put anything but urea in the tank, YES the ECM will know, so stop thinking you can fake it out with anything else. Urea is cheap and will be available everywhere by the time they come out, so RELAX.

ben


-40C give me a break that's nothing, I've seen -70F. Ford is the only company with its head screwed on strait in this respect, I've seen their raptor test vehicles up here some of this this winter and a few times last.

Urea is an organic molecule, held together by hydrogen bonds like any other organic molecule. Of course, like an molecule dipole or not they have London dispersal forces but those are irrelevant.

So tell me how will they determine it? Urea, like ethylene glycol is non-electrolytic. So if they intend to determine it that way then they'd have to add an electrolyte which could be simulated, of just install a resistor where the sensor testing conductivity was. No big deal.

I can't imagine them installing a mass spectrometer on the vehicle even a small one would add a few grand to the sticker prices. So no dice there. And the large ones which are also expensive way I ton, I had to move one into the lab once, nightmare.


Maybe flow rate vs. temperature vs. viscosity. But I also can't imagine that would either be reliable, or hard to fool.

No it would have to be using the same old nox sensing sensors that have been used for the last two decades which are also easy enough to simulate, or tune out once the PCM code is disassembled.

I really don't care how they contrive to do it. With enough intelligence, everything is hackable.

ALL sensors are inherently the same. You send them a signal, they send you a signal, by how much that signal is reduced you determine something. Such as the IAT, the thermocouple contracts with cold => the distance between the metals of different conductivity get smaller=> resistance drops.

o2 sensors. in the presence of oxides of nitrogen the resistance changes ergo the signal changes.

MAF sensor, the air stretches the little springs, resistance rises.

One of my very eccentric professors once told me, when he worked for the air-force doing weapons of defense contracting, if one of his underlings answers to any question was "because the computer said so," they wouldn't get paid, they'd be asked to go home, and they'd usually loose the bid if they were a lower level engineer."

Computers are inherently stupid. I've had the misfortune of using a programming language called MatLab which does a lot of the same stuff the PCM's in the vehicles do, its all tablature based reasoning.

The methods of fooling it may have to become more complex, but computers work on input, and give you an output. All that is needed it to manipulate the input, to get the output you desire.


That is my understanding at least.

They've been running SCR trucks around the world for years.

Read this http://www.factsaboutscr.com/def/default.aspx

And peruse the many links.

-40C give me a break that's nothing, I've seen -70F. Ford is the only company with its head screwed on strait in this respect, I've seen their raptor test vehicles up here some of this this winter and a few times last.

Urea is an organic molecule, held together by hydrogen bonds like any other organic molecule. Of course, like an molecule dipole or not they have London dispersal forces but those are irrelevant.

So tell me how will they determine it? Urea, like ethylene glycol is non-electrolytic. So if they intend to determine it that way then they'd have to add an electrolyte which could be simulated, of just install a resistor where the sensor testing conductivity was. No big deal.

I can't imagine them installing a mass spectrometer on the vehicle even a small one would add a few grand to the sticker prices. So no dice there. And the large ones which are also expensive way I ton, I had to move one into the lab once, nightmare.


Maybe flow rate vs. temperature vs. viscosity. But I also can't imagine that would either be reliable, or hard to fool.

No it would have to be using the same old nox sensing sensors that have been used for the last two decades which are also easy enough to simulate, or tune out once the PCM code is disassembled.

I really don't care how they contrive to do it. With enough intelligence, everything is hackable.

ALL sensors are inherently the same. You send them a signal, they send you a signal, by how much that signal is reduced you determine something. Such as the IAT, the thermocouple contracts with cold => the distance between the metals of different conductivity get smaller=> resistance drops.

o2 sensors. in the presence of oxides of nitrogen the resistance changes ergo the signal changes.

MAF sensor, the air stretches the little springs, resistance rises.

One of my very eccentric professors once told me, when he worked for the air-force doing weapons of defense contracting, if one of his underlings answers to any question was "because the computer said so," they wouldn't get paid, they'd be asked to go home, and they'd usually loose the bid if they were a lower level engineer."

Computers are inherently stupid. I've had the misfortune of using a programming language called MatLab which does a lot of the same stuff the PCM's in the vehicles do, its all tablature based reasoning.

The methods of fooling it may have to become more complex, but computers work on input, and give you an output. All that is needed it to manipulate the input, to get the output you desire.


That is my understanding at least.

then dont buy one. problem solved.

MAF sensor, the air stretches the little springs, resistance rises.

Wanna try that one again???

I wasn't blessed with intelligence like yourself so please type slower for me. This is the second thread (click) (http://www.dieselplace.com/forum/showpost.php?p=3731674&postcount=27) that you have posted this same comment...yet you haven't explained much on how it works. It must bother you there or those that do not know how the DEF/Urea system works in cold weather.
Like the above post says, please explain how the system works and how GM designed it to work in cold weather like my original question asks.

the tank has a heater and many other measures to ensure proper operation when its cold. The engine doesnt start using the urea until its reached a sufficient temperature and thawed enough. Its not like, omg, 11*, limp mode!!! There will be multiple redundancy features, not to mention the fact that if the urea system were to totally fail or fall off the truck, its not like the truck slams on the brakes on the highway and comes to a dead stop. :rolleyes: It gives you a couple warnings that says "speed limited to 55mph UPON RESTART" So if you are at the north pole and hit a rock and the urea tank falls off, you will be able to shut the truck off and restart it a couple times until it says "speed limited to 5mph upon restart"...if thats the case then dont shut it off until you can get to a dealer. If you guys are in your hard core -190* climates working on the oil fields then you most likely arent going to be shutting the trucks off anyways.

The engine will NEVER shut off no matter how long you run it/how many times you restart it with the urea tank empty. The most severe limp mode will limit it to 5mph (or it might be 7mph, I forget).

If you dont like it, then DONT BUY ONE. It is what it is. This is the EPA mandating these specifications. Whining and complaining isnt going to make it go away so save your guys' breath. :)

just an idea, wait until it comes out, give it a chance to be proven, THEN you can complain. :D

ben

then dont buy one. problem solved.


Why do you say that? I wouldn't buy one up here anyway, its too cold for any kind of diesel in my opinion. I'll stick to my 6.0L, anemic as it is in comparison because at least its very warm blooded.

What I was saying was that no matter what provisions they install they can be reversed.

I am very much opposed to any technology that can strand a vehicle. You say they'll allow a a warm up period? Well if they're testing at -40 and they tune it to warm up from -40 then if its -60 it'll still be frozen and the truck will be stranded.

Lets say you or someone you love is driving one of these time bombs and it cold and freezes down, or the sensor breaks, or the PCM malfunctions. Is injecting a concentrated element most often found in urine into the tailpipe more valuable then their lives and safety?

They can do this but they better make damn sure they've got it right, because if it gets one person stuck and harms or kills just just that one person its absolutely not worth it.

I'll give you an example of another technology like this that I've seen. For a long time, and I'm not sure if they still do, ford put a switch that senses impact and cuts off the fuel pump in a lot of their cars. The switch is sensitive enough that if the car hits a patch of packed snow just right the fuel pump stops. If they don't know how reset it they're in a lot of trouble. I've never heard of this killing anyone but I've heard of a lot of people getting stranded and getting frostbite from it.

Goals should be as follows

safety > utility > emissions, not the other way around.

the tank has a heater and many other measures to ensure proper operation when its cold. The engine doesnt start using the urea until its reached a sufficient temperature and thawed enough. Its not like, omg, 11*, limp mode!!! There will be multiple redundancy features, not to mention the fact that if the urea system were to totally fail or fall off the truck, its not like the truck slams on the brakes on the highway and comes to a dead stop. :rolleyes: It gives you a couple warnings that says "speed limited to 55mph UPON RESTART" So if you are at the north pole and hit a rock and the urea tank falls off, you will be able to shut the truck off and restart it a couple times until it says "speed limited to 5mph upon restart"...if thats the case then dont shut it off until you can get to a dealer. If you guys are in your hard core -190* climates working on the oil fields then you most likely arent going to be shutting the trucks off anyways.

The engine will NEVER shut off no matter how long you run it/how many times you restart it with the urea tank empty. The most severe limp mode will limit it to 5mph (or it might be 7mph, I forget).

If you dont like it, then DONT BUY ONE. It is what it is. This is the EPA mandating these specifications. Whining and complaining isnt going to make it go away so save your guys' breath. :)

just an idea, wait until it comes out, give it a chance to be proven, THEN you can complain. :D

ben


You're still adding a lot of complexity, also speed limited to 5mph. There are hills that I know of on the way to friends cabins that you can't climb going less than 35 mph when they are iced over. What is this urea tank heater runnning off of? If it battery power then you're draining the battery, if its external then you've got a problem because that assumes there are plug-ins everywhere.

I'm not complaining about the device itself it may work fine, I just don't like the idea of a little nany feature that has propriety over the drivetrain.

I am very much opposed to any technology that can strand a vehicle..

hahaha I always crack up when I see people say this with the utmost confidence that their "simple" vehicle is immune to failure.

If you are opposed to any technology that can strand a vehicle when you are in the middle of nowhere, why arent you driving a 1940's dodge power wagon???

Honestly. Your 6.0 has drive-by-wire, more wiring than you will ever know, over 10 individual computers, no distributor, 20+ sensors, and an engine that wont even crank/turnover with a dead ECM. BUT. I think thats a good plan sticking with the 6.0, technological failures arent possible with those like they will be with the new dmax's.

quit your current job and apply for head engineer at GM Powertrain. You seem to have everything all figured out how to make it reliable and not fail like you are assuming the new dmax emissions systems will.

Im sure old timers scoffed at power steering when it was invented too. :rolleyes:

ben

Why do you say that?

because you are obviously stubborn and thickheaded to the point where you will never trust anything so its not worth wasting your breath scaring off everyone else from buying one; Im 100% confident it will work in 99% of all the conditions they will see in the real world.

Oh, and for that 1%, maybe you should just keep a bicycle in the bed of the truck then.

hahaha I always crack up when I see people say this with the utmost confidence that their "simple" vehicle is immune to failure.

If you are opposed to any technology that can strand a vehicle when you are in the middle of nowhere, why arent you driving a 1940's dodge power wagon???

Honestly. Your 6.0 has drive-by-wire, more wiring than you will ever know, over 10 individual computers, no distributor, 20+ sensors, and an engine that wont even crank/turnover with a dead ECM. BUT. I think thats a good plan sticking with the 6.0, technological failures arent possible with those like they will be with the new dmax's.

quit your current job and apply for head engineer at GM Powertrain. You seem to have everything all figured out how to make it reliable and not fail like you are assuming the new dmax emissions systems will.

Im sure old timers scoffed at power steering when it was invented too. :rolleyes:

ben


Oh, really drive-by-wire and ten computers? Really? What are they called because I can think of two unless you're counting the relay boxes, fuse boxes, the wiper motor and HVAC control resister board ect... More like one PCM, a BCM for a few other features, and cable drive. They didn't add drive-by-wire until late 2003. The only sensors it really needs to run is the o2, manifold absolute pressure, and tps. Everything else is just refinement.

Kill power the the 80e and it should still drive iirc (albiet only in 2nd gear limp /w no lockup).

IAT and ECT add enrichment based on engine temp and work a few cold weather abuse features (slightly limited revs and whatnot), and adjust idle. If you disconnect both the computer reverts to whatever the coldest reading it can send it (its either -38 or -40 I can't recall).

Take out the MAF and it'll revert to speed density. A little less mileage becase that's open loop but it will run just fine.

I don't think it will run only on MAF without the MAP the MAP is essential.

And it will run, but I don't think it would be very drivable without the TPS.

o2's? not sure if it would run without those. I don't think that it would, the rear ones don't matter but with no front o2's it will at least run very very strangely. If at all.

The crank and cam, and knock sensor, also not entirely necessary, not all of them at least, they just allow the PCM to pull timing during pre-det. So you'll have a few less hp because it will run with timing pulled all the time but no big deal. As long as there is one of the reluctor senors still connected the PCM should still know when to fire the coil packs.

VSS, like the TPS you won't have downshifts but that won't strand you either.

The point is there are really only a few critical sensors, and they're usually redundant or partially redundant like the o2's or the crank and cam sensor and the knock sensors.

Does the truck really need an IAT and and ECT, no but its nice to have both and average the values so that when you start the truck when its warm it has warm idle and closed loop enrichment instead of assuming because the IAT says it's -20 that it should be in open loop.

I am an engineering student, I may very well work at GM one day.

And you're right I did have an old Dodge, not quite a 1940 it was an 86 D250, but it was very reliable albeit outdated.

And in the summer I do have my biked locked in the bed of my truck.


And for what it's worth, I love technology. If I ever got an old truck to play with, the very first thing I'd do is convert to EFI, or swap in a modern computer controlled diesel. There's no advantage to carb, not even reliability especially when in the cold. If it was already an old diesel I might leave it be initially, but I'd want more power eventually.

I just see no point in creating one more thing to go wrong without very good reason. If it just threw an obnoxious CEL like low fuel or wiper fluid does that would be enough to get almost all owners to top it off. They don't need to be messing with the speed limiters. I'd actually be fine if it just limited to 55, anything below that is making it unsafe. As I've always said, speed doesn't kill, differences in speed kill. Making a vehicle only capable of doing a small fraction of the speed limit is just asking for trouble.

And I know its not GM, its the EPA. I just don't agree with such practices.

the tank has a heater and many other measures to ensure proper operation when its cold. The engine doesnt start using the urea until its reached a sufficient temperature and thawed enough. Its not like, omg, 11*, limp mode!!!

If you dont like it, then DONT BUY ONE. It is what it is. This is the EPA mandating these specifications. Whining and complaining isnt going to make it go away so save your guys' breath. :)

just an idea, wait until it comes out, give it a chance to be proven, THEN you can complain. :D

ben

Beautiful...that is what I am looking for...the "many other measures" to quote you. You know they are there...does anyone know what they are?

I just grabbed a couple beers and am sitting back and watching this with amusement.

Yunz guys amaze me. The Urea storage tank is heated via the engine coolant, or a heating element.
MAF sensors (at least on the one's I've seen) don't have "springs".
Urea contributes to a chemical reaction, post combustion, much like an air pump helps keep a catalytic convertor lit.

Here's a nice video http://www.everytime.cummins.com/every/misc/Technology/DEF_page.page

and here's a nice Q & A http://www.cumminsfiltration.com/pdfs/product_lit/americas_brochures/MB10033.pdf

Yunz guys amaze me. The Urea storage tank is heated via the engine coolant.
MAF sensors (at least on the one's I've seen) don't have "springs".
Urea contributes to a chemical reaction, post combustion, much like an air pump helps keep a catalytic convertor lit.


The vane meter style (not the kind chevy uses) uses a spring loaded plate. The ones chevy use heat up and the air flowing past them decreases the temperature changes the resistance. I got the two a little bit confused its still the same premise. Computer sends a signal, computer receives a signal, depending on that signal it decides how to operate.

Good contribution on it begin heated by coolant that makes more sense.

The vane meter style (not the kind chevy uses) uses a spring loaded plate. The ones chevy use heat up and the air flowing past them decreases the temperature changes the resistance. I got the two a little bit confused ts still the same premise.

Good contribution on it begin heated by coolant that makes more sense.

PS. I added two links:D

I've been reading this post and its hilarious!!! You guys have to use some common sense.... Its not like the tank just runs out with no warning. It's like being pissed at GM because you ran your truck out of diesel and it shut off.

The system won't start working till the truck is at a certain operating temp and the temp in the DEF tank is above freezing. It will just have a 12 volt heater in it simaliar to the block heater just not 110v.

I don't see it being anything to stress out about it you don't want it then take the system off. Just like everyone that has taken the DPF off. Trust me there will be a kit.

I've been reading this post and its hilarious!!! You guys have to use some common sense.... Its not like the tank just runs out with no warning. It's like being pissed at GM because you ran your truck out of diesel and it shut off.

The system won't start working till the truck is at a certain operating temp and the temp in the DEF tank is above freezing. It will just have a 12 volt heater in it simaliar to the block heater just not 110v.

I don't see it being anything to stress out about it you don't want it then take the system off. Just like everyone that has taken the DPF off. Trust me there will be a kit.

Many manufacturers will include some type of gauge to indicate the need to add DEF.

As for removal/ bypass, Shirley it will exist, but just like any other emissions/ PCM system component, us fleet guys don't need to be looking over our shoulder. And many of us don't wish to argue over warranty claims, ever.
Fear of the unknown, and the resistance to using Google, or it's equivalent, is all I see going on here.


These systems have been fleet tested and IN production for years, in many different variations.

Oh, really drive-by-wire and ten computers? Really? What are they called because I can think of two unless you're counting the relay boxes, fuse boxes, the wiper motor and HVAC control resister board ect... More like one PCM, a BCM for a few other features, and cable drive. They didn't add drive-by-wire until late 2003. The only sensors it really needs to run is the o2, manifold absolute pressure, and tps. Everything else is just refinement.

Kill power the the 80e and it should still drive iirc (albiet only in 2nd gear limp /w no lockup).

IAT and ECT add enrichment based on engine temp and work a few cold weather abuse features (slightly limited revs and whatnot), and adjust idle. If you disconnect both the computer reverts to whatever the coldest reading it can send it (its either -38 or -40 I can't recall).

Take out the MAF and it'll revert to speed density. A little less mileage becase that's open loop but it will run just fine.

I don't think it will run only on MAF without the MAP the MAP is essential.

And it will run, but I don't think it would be very drivable without the TPS.

o2's? not sure if it would run without those. I don't think that it would, the rear ones don't matter but with no front o2's it will at least run very very strangely. If at all.

The crank and cam, and knock sensor, also not entirely necessary, not all of them at least, they just allow the PCM to pull timing during pre-det. So you'll have a few less hp because it will run with timing pulled all the time but no big deal. As long as there is one of the reluctor senors still connected the PCM should still know when to fire the coil packs.

VSS, like the TPS you won't have downshifts but that won't strand you either.

The point is there are really only a few critical sensors, and they're usually redundant or partially redundant like the o2's or the crank and cam sensor and the knock sensors.

Does the truck really need an IAT and and ECT, no but its nice to have both and average the values so that when you start the truck when its warm it has warm idle and closed loop enrichment instead of assuming because the IAT says it's -20 that it should be in open loop.

I am an engineering student, I may very well work at GM one day.

And you're right I did have an old Dodge, not quite a 1940 it was an 86 D250, but it was very reliable albeit outdated.

And in the summer I do have my biked locked in the bed of my truck.


And for what it's worth, I love technology. If I ever got an old truck to play with, the very first thing I'd do is convert to EFI, or swap in a modern computer controlled diesel. There's no advantage to carb, not even reliability especially when in the cold. If it was already an old diesel I might leave it be initially, but I'd want more power eventually.

I just see no point in creating one more thing to go wrong without very good reason. If it just threw an obnoxious CEL like low fuel or wiper fluid does that would be enough to get almost all owners to top it off. They don't need to be messing with the speed limiters. I'd actually be fine if it just limited to 55, anything below that is making it unsafe. As I've always said, speed doesn't kill, differences in speed kill. Making a vehicle only capable of doing a small fraction of the speed limit is just asking for trouble.

And I know its not GM, its the EPA. I just don't agree with such practices.

LMAO a crank sensor on 6.0's or ls motors is essential, the truck/car will NOT even start without one... the cam sensor does not matter for starting/running. I had a crank sensor that just crapped out in the middle of a race, I was at the 1000 ft mark car just DIED.......... Would not re start, no codes. But it was sending a crank signal, slightly, so our scanner showed it. Would not start, so I replaced the cam sensor, no change, swapped it back, replaced the crank sensor, bingo. If the cam sensor goes, the pcm reverts to the crank only.....otherwise it uses the cam sensor to fine tune where the engines at. And the ect is not required to start, but good luck running well without it.
02's are not required if you tune the car in open loop, mine is...

LMAO a crank sensor on 6.0's or ls motors is essential, the truck/car will NOT even start without one... the cam sensor does not matter for starting/running. I had a crank sensor that just crapped out in the middle of a race, I was at the 1000 ft mark car just DIED.......... Would not re start, no codes. But it was sending a crank signal, slightly, so our scanner showed it. Would not start, so I replaced the cam sensor, no change, swapped it back, replaced the crank sensor, bingo. If the cam sensor goes, the pcm reverts to the crank only.....otherwise it uses the cam sensor to fine tune where the engines at. And the ect is not required to start, but good luck running well without it.
02's are not required if you tune the car in open loop, mine is...


Alright so it was the cam sensor it could do without, happy? I guess I was thinking it could run without the crank sensor being indexed with the CASE relearn in which case it wasn't using it at all. I was perhaps, mistaken.

So if you're berating my observations, does that mean you're agreeing with the the person whom I was responding too who believed the LQ4 needed 10 computers to operate? Saying the the GenIII engines are complicated to that extent is a little more laughable than mixing up two sensors.

Well I read bits and pieces of this thread so I hope I did not miss it, but liquids expand when they freeze (ever left a full beer bottle in the truck when it is -20C out). What happens to that tank when you have it full and it freezes and starts to expand?

Well I read bits and pieces of this thread so I hope I did not miss it, but liquids expand when they freeze (ever left a full beer bottle in the truck when it is -20C out). What happens to that tank when you have it full and it freezes and starts to expand?
Why not read the Q & A link:rolleyes:?


Q. Does DEF expand when frozen?

A. Yes, DEF expands by approximately 7% when frozen. DEF packaging and tanks are designed to allow for expansion.

ok where do I start

Oh, really drive-by-wire and ten computers? Really? What are they called because I can think of two unless you're counting the relay boxes, fuse boxes, the wiper motor and HVAC control resister board ect....

well you didnt specify what year yours was. Starting in 2001 many of the gen III V8's were drive by wire, and others were drive by cable. Thats why when you build a 2002 or earlier truck in the tech 2 the first thing it asks is "with throttle actuated control" or "w/o throttle actuated control"

Depending on what year it is, and what trim level your truck is. 2003+ could have a ton, if you really want me to list everything that communicates on the common class 2 bus I can. PCM/ECM, TCM, CCM, EBCM, BCM, SDM, IPC, radio, CDX, RSE, RSA, MSM, TCSM, VCIM, amplifier, DRR, RWSM, RCM, I dont know Im probably missing a couple more.

The 99-02's had a significantly less amount, PCM, TCM (allison trans only), BCM, SDM, IPC, radio (E&C bus), CCM (E&C bus, if you have the automatic climate control setup), CD player (E&C bus), EBCM, VCIM (if you have onstar), and a TCSM.


They didn't add drive-by-wire until late 2003.....

no, late 2002 with the beginning of the 2003MY, everything went drive by wire. The only exception was the 4.3 V6 which didnt go to drive by wire until 2007 with the new body style

The only sensors it really needs to run is the o2, manifold absolute pressure, and tps. Everything else is just refinement......

bwaahhaha... go unplug your MAF, CKP, CPS, IAC and tell me how well it runs, if at all. :rolleyes:

Kill power the the 80e and it should still drive iirc (albiet only in 2nd gear limp /w no lockup).

the allison is the same way, unplug everything and you'll still have third gear and reverse...so whats your point?

IAT and ECT add enrichment based on engine temp and work a few cold weather abuse features (slightly limited revs and whatnot), and adjust idle. If you disconnect both the computer reverts to whatever the coldest reading it can send it (its either -38 or -40 I can't recall).).

slightly limited rpms?????? It will run like absolute shit! Ive done more than a few GM engine swaps into various other vehicles/jeeps/offroad buggy's whatever and trust me, if you are missing any of the sensors I mentioned above, it will barely run.


Take out the MAF and it'll revert to speed density. A little less mileage becase that's open loop but it will run just fine.

not without a custom tune it wont.

I don't think it will run only on MAF without the MAP the MAP is essential..

yes, it will start and run with only the MAF hooked up (no MAP), but like I said above, run like crap.


And it will run, but I don't think it would be very drivable without the TPS.

correct!!!

o2's? not sure if it would run without those. I don't think that it would, the rear ones don't matter but with no front o2's it will at least run very very strangely. If at all.

that is incorrect. It will run fine without the o2's hooked up, but it will just run in open loop. You do know the PCM doesnt even start taking O2 readings until the engine is up to temp right....????

The crank and cam, and knock sensor, also not entirely necessary, not all of them at least, they just allow the PCM to pull timing during pre-det. So you'll have a few less hp because it will run with timing pulled all the time but no big deal. As long as there is one of the reluctor senors still connected the PCM should still know when to fire the coil packs.

not entirely necessary??? You really need to sit down with a service manual and read it front to back. Yeah an old TBI, CPI, or small block vortec from the early/mid 90's might run without those. Try it on a Gen III V8 and tell me how far you get.... :)


VSS, like the TPS you won't have downshifts but that won't strand you either.

VSS is probably the least important sensor, yes you got that correct. The idle might be goofy and fuel mileage will suffer slightly due to lack of DFCO, but it probably wouldnt even be noticible.,

The point is there are really only a few critical sensors, and they're usually redundant or partially redundant like the o2's or the crank and cam sensor and the knock sensors.


knock sensors arent really important, at least not as important as you are making them out to be. GM tunes the LSx engines so ridiculously conservatively that you very rarely see a stock tuned truck go into KR. Cam and crank sensors are not redundant of eachother. The engine wont even run with no CKP signal. It will run, but like crap with no CPS signal.




Does the truck really need an IAT and and ECT, no but its nice to have both and average the values so that when you start the truck when its warm it has warm idle and closed loop enrichment instead of assuming because the IAT says it's -20 that it should be in open loop.


Yes it does need them! Thats the whole point of EFI!! To be able to start and run smoothly (without a choke or anything, remember carbs??) in every possible range of temperatures and conditions. If you deleted the ECT and IAT sensors and programmed the VE and PE tables to reflect a normal 70* day it wouldnt even start at -10*.


I am an engineering student, I may very well work at GM one day.


first you need to read up on how GM engines work... ;)


I'd actually be fine if it just limited to 55, anything below that is making it unsafe. As I've always said, speed doesn't kill, differences in speed kill. Making a vehicle only capable of doing a small fraction of the speed limit is just asking for trouble.




once again, stubborn and assuming the worst without even reading any of the TRUE technical background info on SCR systems (not just what everyone else says out of their bum). Youre driving along; you run out of urea (after being yelled at by bells and whistles for the past 1000 miles), is the truck going to immediately shut down and go to 5mph? UM NO. Its going to ding at you and say in the driver info center "SPEED LIMITED UPON RESTART". RESTART. So unless you pull over on the highway and shut off your truck and restart it, You arent gonna die from being run over because the truck running out of urea.


AND. When you restart the truck, it dings at you and says "warning! diesel exhaust fluid empty, speed limited to 55mph (or 5mph)". So before you even back out of your garage or parking space, you know what you are limited too.



rant off...im sorry but this just frustrates me the whole fact that everyone basically knows nothing about this new system and theyre already assuming the worst and that its gonna be a hugeass failure and the end of reliable diesels. :(

ben

rant off...im sorry but this just frustrates me the whole fact that everyone basically knows nothing about this new system and theyre already assuming the worst and that its gonna be a hugeass failure and the end of reliable diesels. :(

ben

I stayed at a Holiday Inn Express. Does that mean I don't understand it either?

C'mon, it's not like were talking about the "On-star speaker":cool:


This same crap goes on everytime some better mousetrap comes down the pipe. EFI, DPF, catalytic convertor, automatic transmission, etc. Wait 'til 24V and higher starting systems come along:rolleyes:.

My applogies. I did not go into the links.

Alright so it was the cam sensor it could do without, happy? I guess I was thinking it could run without the crank sensor being indexed with the CASE relearn in which case it wasn't using it at all. I was perhaps, mistaken.

So if you're berating my observations, does that mean you're agreeing with the the person whom I was responding too who believed the LQ4 needed 10 computers to operate? Saying the the GenIII engines are complicated to that extent is a little more laughable than mixing up two sensors.


Hell no an Lq4 doesnt REQUIRE 10 computers to run, technically only 1 to "run" but there probably are 10 "computers" in your truck.

But I do find you funny, you are a greenie, aka noobie. You dont have experience with these enough (student) to be half as cocky as you make yourself. When I went to tech school I was the same way, sort of, we all were, but you learn quickly, that you really know shit when you get out.

FWIW, kick it back a notch and accept that you dont know everything.

After I graduated I learned a hell of a lot more then when I was in school. I also learned that a lot, I mean a lot of engineer's and architect's mess up entirely too much.

Wow, I'm impressed I started this. Rather enjoying it.
--DuratotheMax--- I went through and read some of your other posts in other threads...Are you on a mission to prove how "stupid" people are? Short and skinny, we are all stupid!!! Have you ever met anyone that thinks they are in the avg & below group? I never have, NOR do I think I am...like everyone else. Who is wrong?

Like most long replies...I don't say much so stop reading now.

I've been reading this post and its hilarious!!! You guys have to use some common sense....

Yep your right, it is funny, I will give you that. That is why I said I am grabbing a couple beers and watching in amusement.

Here's my take on this whole topic and pretty much what this forum is turning into. I have only been on this forum for 1.5 years so it is limited at best.
In my limited time, people are going from just asking questions to starting their threads with, "First off... MANY humble apologies if I'm duplicating other conversations. I've done a search and really couldn't find where this has been discussed." (click to see the thread) (http://www.dieselplace.com/forum/showthread.php?t=355999).

I am now starting to think, what is the history behind the forum when people have to apologize before they ask questions.
I'm an engineer and will be the first to tell you I didn't study every damn thing on earth involving engineering. There are many specialties in engineering...maybe the reason there are so many different engineering programs.

Lets step off the high horse and just answer questions instead of trying to prove how much smarter you/we are then the next person. Hell I've gone through calc I II & III, statics & dynamics, and differential equations. I probably would not be able to do those classes again without failing. Thought process...that is what learned.

Either answer the question or ignore the guy who, "does not have any common sense."

No one makes anyone read these threads and respond. Usually we see a topic we are interested in and click the thread. We read it and think..."You must be the umteenth million guy that asked this!" Well, cut joe bag of donuts some slack and either don't answer or point them in the direction they are asking.

Now, back to my beer to enjoy watching how many people rip my ass for these comments...sad thing is, you can't ask questions on this forum anymore without retribution in some way shape or form from some smart ass that knows all and has to point it out. So it is fun to poke and prod people to get the reaction we get...you know, if you question what someone knows, or ask to prove it, they will give "BIG" responses...kinda like this one I just did. Thanks guys, I do enjoy this forum.

ok where do I start



well you didnt specify what year yours was. Starting in 2001 many of the gen III V8's were drive by wire, and others were drive by cable. Thats why when you build a 2002 or earlier truck in the tech 2 the first thing it asks is "with throttle actuated control" or "w/o throttle actuated control"

Depending on what year it is, and what trim level your truck is. 2003+ could have a ton, if you really want me to list everything that communicates on the common class 2 bus I can. PCM/ECM, TCM, CCM, EBCM, BCM, SDM, IPC, radio, CDX, RSE, RSA, MSM, TCSM, VCIM, amplifier, DRR, RWSM, RCM, I dont know Im probably missing a couple more.

The 99-02's had a significantly less amount, PCM, TCM (allison trans only), BCM, SDM, IPC, radio (E&C bus), CCM (E&C bus, if you have the automatic climate control setup), CD player (E&C bus), EBCM, VCIM (if you have onstar), and a TCSM.




no, late 2002 with the beginning of the 2003MY, everything went drive by wire. The only exception was the 4.3 V6 which didnt go to drive by wire until 2007 with the new body style



bwaahhaha... go unplug your MAF, CKP, CPS, IAC and tell me how well it runs, if at all. :rolleyes:



the allison is the same way, unplug everything and you'll still have third gear and reverse...so whats your point?



slightly limited rpms?????? It will run like absolute shit! Ive done more than a few GM engine swaps into various other vehicles/jeeps/offroad buggy's whatever and trust me, if you are missing any of the sensors I mentioned above, it will barely run.




not without a custom tune it wont.



yes, it will start and run with only the MAF hooked up (no MAP), but like I said above, run like crap.




correct!!!



that is incorrect. It will run fine without the o2's hooked up, but it will just run in open loop. You do know the PCM doesnt even start taking O2 readings until the engine is up to temp right....????



not entirely necessary??? You really need to sit down with a service manual and read it front to back. Yeah an old TBI, CPI, or small block vortec from the early/mid 90's might run without those. Try it on a Gen III V8 and tell me how far you get.... :)




VSS is probably the least important sensor, yes you got that correct. The idle might be goofy and fuel mileage will suffer slightly due to lack of DFCO, but it probably wouldnt even be noticible.,




knock sensors arent really important, at least not as important as you are making them out to be. GM tunes the LSx engines so ridiculously conservatively that you very rarely see a stock tuned truck go into KR. Cam and crank sensors are not redundant of eachother. The engine wont even run with no CKP signal. It will run, but like crap with no CPS signal.







Yes it does need them! Thats the whole point of EFI!! To be able to start and run smoothly (without a choke or anything, remember carbs??) in every possible range of temperatures and conditions. If you deleted the ECT and IAT sensors and programmed the VE and PE tables to reflect a normal 70* day it wouldnt even start at -10*.





first you need to read up on how GM engines work... ;)







once again, stubborn and assuming the worst without even reading any of the TRUE technical background info on SCR systems (not just what everyone else says out of their bum). Youre driving along; you run out of urea (after being yelled at by bells and whistles for the past 1000 miles), is the truck going to immediately shut down and go to 5mph? UM NO. Its going to ding at you and say in the driver info center "SPEED LIMITED UPON RESTART". RESTART. So unless you pull over on the highway and shut off your truck and restart it, You arent gonna die from being run over because the truck running out of urea.


AND. When you restart the truck, it dings at you and says "warning! diesel exhaust fluid empty, speed limited to 55mph (or 5mph)". So before you even back out of your garage or parking space, you know what you are limited too.



rant off...im sorry but this just frustrates me the whole fact that everyone basically knows nothing about this new system and theyre already assuming the worst and that its gonna be a hugeass failure and the end of reliable diesels. :(

ben



The point was that from your previous post you seemed to think that the truck needed all kinds of sensors and electronics to run. Not run well, but simply to run at all. I was just clearing that up, albeit in a rather meandering and long winded way.

Am I an expert when it comes to any of this? No, I'm not. Currently I'm not planning on making making a profession out of it, its just something that interests me.

My responses haven't been inflammatory, or at least that wasn't their intention. I haven't called anyone names, and if I've directly insulted someone it was unintentional.

People get much to worked up over threads like these.

People get much to worked up over threads like these.

It's like the newspaper companies..."If it bleeds, it reads!!!". Fights attract people.
Back to the original question. How does the system work in cold weather? I was surprised when the one fellow mentioned the tank was under the hood. I thought the DEF tank was near the fuel tank. That alone explains using the vehicles cooling system to thaw the DEF tank. I was thinking...how do they route the cooling lines back to the fuel system...shows how basic I am.

i think ''duratothemax'' just wants the real facts out ,as it helps everybody learn how these cars/trucks work,,i aprecate most every post he puts out ,and i learn alot,,maybe some guys here should read a gm factory service manual and work on these cars everyday ,for 5-10 years ,like i do,computers are so much a part of these diesel trucks and 638hp zr-1 corvettes ,you can't live with-out them

i think ''duratothemax'' just wants the real facts out ,as it helps everybody learn how these cars/trucks work,,i aprecate most every post he puts out ,and i learn alot,,maybe some guys here should read a gm factory service manual and work on these cars everyday ,for 5-10 years ,like i do,computers are so much a part of these diesel trucks and 638hp zr-1 corvettes ,you can't live with-out them
I agree, I think DuratotheMax probably knows more than most of us combined...I don't dispute that and I don't know him personally. If I knew him, I would probably say he is not wrong at much.
Reading his replies I haven't found much he was wrong at. However, tacked is a key element. That he lacks...When you know it all, and the more I read the more I think he really does know it all, tacked is important.
The smartest guy on earth is still an asshole when they don't have any approach on how they tell someone the difference between the birds and the bees.
You may be good at pointing out how someone is wrong at what they think/do...but can you explain to me/them on how we are wrong...and convince us on WHY we should change what we are doing. That is the objective...It's called a Coach.

The smartest guy on earth is still an asshole when they don't have any approach on how they tell someone the difference between the birds and the bees.
"Tacked" should really be "Tact", right;)

I'll admit DURAtotheMAX has made some very good arguments. I still don't care for the concept, but I'm more confident that they can get it to work in cold climates now, than I was at the begging of the discussion.

Which I suppose the the whole point of a debate.

I agree, I think DuratotheMax probably knows more than most of us combined...I don't dispute that and I don't know him personally. If I knew him, I would probably say he is not wrong at much.
Reading his replies I haven't found much he was wrong at. However, tacked is a key element. That he lacks...When you know it all, and the more I read the more I think he really does know it all, tacked is important.
The smartest guy on earth is still an asshole when they don't have any approach on how they tell someone the difference between the birds and the bees.
You may be good at pointing out how someone is wrong at what they think/do...but can you explain to me/them on how we are wrong...and convince us on WHY we should change what we are doing. That is the objective...It's called a Coach.
just remember its late at night

why the F are you guys arguing about this? :D

can we wait until the trucks are actually for sale?

jeez.

why the F are you guys arguing about this? :D

can we wait until the trucks are actually for sale?

jeez.

Yeah:p:

I cannot order a '10 today, and if I want an '11, I can't order it 'til March, and it won't be on the ground 'til late September. GM sux when it comes to ordering a truck, period.

But I can get an '11 Stupid Duty in 8 weeks from today:mad:.

Now that you said that I know you'll get some snickers from those badass rugged more manly than everyone else in the world guys who live/work in the yukon territory, where it gets -150* and not -30* like in kapaskasing. :D :rolleyes:

ben


I've seen it a lot colder then -30 in kap. I used to live in opasatika, only a few miles down the road! I've seen -45 an a foot of snow in september alone!

Do you any of you guys fly on airplanes?!

I would hate to be like some of you, so worried sick about mechanical failure while at 40,000 feet....

Do you any of you guys fly on airplanes?!

I would hate to be like some of you, so worried sick about mechanical failure while at 40,000 feet....

exactly. :D

The two biggest technical changes Arvan shared details about are the Duramax’s all-new selective catalytic reduction and its enhanced exhaust gas recirculation systems -- which are needed to scrub NOx down to no more than .2 grams per horsepower/hour -- as well as its approved use of B20 biodiesel. That’s 80 percent ultra-low-sulfur diesel and 20 percent biodiesel.
NOx selective catalytic reduction uses diesel exhaust fluid. The urea-based solution (32.5 percent industrial urea and 67.5 percent deionized water) is held in a 5.5-gallon storage tank and injected as a fine mist into the Duramax’s hot exhaust gases. The heat turns the urea into ammonia that -- when combined with a special catalytic converter -- breaks the NOx down into harmless nitrogen gas and water vapor.
The exhaust fluid refill point for the HD pickups is mounted under the hood of the engine, while the vans’ is positioned next to the fuel door on the side of the vehicle. The tank is mounted on the side of the driver-side frame rail.
Arvan says diesel exhaust fluid refill intervals will vary depending on duty cycle. Some customers will only have to refill during routing maintenance, such as when the oil is changed, while others will have to top off the tank sooner.
http://blogs.cars.com/.a/6a00d83451b3c669e20120a4eb4d87970b-800wi

“If they’re towing frequently, they’ll [likely] have to fill up with DEF again sooner,” Arvan said.
To ensure that the exhaust fluid tank is refilled, Duramax-equipped trucks will warn the driver when the fluid is down to a 1,000-mile range. A series of start-up warnings -- including lights, chimes and messages -- will become more frequent until the tank is empty. If the driver continues to operate the truck with a dry tank, after a final warning and restart the truck will only operate in a “limp-home” mode that limits speed to just 5 mph until the tank is refilled.
The selective catalytic reduction and diesel-particulate filter systems depend on a diesel oxidation catalyst that’s positioned downstream, behind the engine, to start the NOx and soot-scrubbing processes. The catalyst requires high temperatures to perform. Those temperatures are achieved on-demand by the addition of a new fuel injector that’s been positioned directly behind the exhaust outlet of the Duramax’s variable-geometry turbo instead of using the engine’s eight existing in-cylinder injectors. Fuel is squirted into the hot exhaust and burns, quickly raising temperatures in the catalysts.

From here http://news.pickuptrucks.com/2009/08/first-look-2011-duramax-diesel-v8-engine.html

No mention of the Onstar speaker, though:rolleyes:

No mention of the Onstar speaker, though:rolleyes:

dont you hate it when it starts making noise? I hear that spaying lubricant in it stops the speaker from making noise. :D

dont you hate it when it starts making noise? I hear that spaying lubricant in it stops the speaker from making noise. :DJust :stirthepo

and :hug:to all.

LOL to this whole thread

water is the best lubricant because I figured out that the speaker foam gets dried out and starts that horrible noise. It just needs some moisture so I spray mine with a garden hose about every week or so.

So I was interested in what my media rep representative at GM says about all this so he called the engineers in Detroit so it doesn't get closer to the truth than this. I asked the questions all raised here.

Al V
www.fastkap.com

From GM PR rep:
Excellent questions. Here is what my truck engineers tell me:

There is a heater in the line that feeds the DEF injector to the exhaust. This will allow for enough fluid availability until a heat exchanger in the tank thaws out the fluid. Only a very small volume of DEF fluid is needed ( about 1% of the fuel that is used)

The fluid can freeze/thaws any number of times and still be functional (its 1/3 urea and 2/3 water and is mixed in this proportion to give it the lowest possible freeze point like antifreeze)
The tank has been validated to handle the expansion cycles - FYI DEF freezes and thaws very uniformly as the urea stays in solution- not like water and sugar, for ex.
Also, this system was tested for validation over the last 2 winters in Yellowknife.


Let me know if you have any other questions and/or concerns.
Take care,

G S
Product Communications
General Motors of Canada Limited

So I was interested in what my media rep representative at GM says about all this so he called the engineers in Detroit so it doesn't get closer to the truth than this. I asked the questions all raised here.

Al V
www.fastkap.com (http://www.fastkap.com)

From GM PR rep:
Excellent questions. Here is what my truck engineers tell me:

There is a heater in the line that feeds the DEF injector to the exhaust. This will allow for enough fluid availability until a heat exchanger in the tank thaws out the fluid. Only a very small volume of DEF fluid is needed ( about 1% of the fuel that is used)

The fluid can freeze/thaws any number of times and still be functional (its 1/3 urea and 2/3 water and is mixed in this proportion to give it the lowest possible freeze point like antifreeze)
The tank has been validated to handle the expansion cycles - FYI DEF freezes and thaws very uniformly as the urea stays in solution- not like water and sugar, for ex.
Also, this system was tested for validation over the last 2 winters in Yellowknife.


Let me know if you have any other questions and/or concerns.
Take care,

G S
Product Communications
General Motors of Canada Limited

Out of all the B.S. answers...this is what I was looking for. Something that actually explains the system somewhat. Like I said before, make it simple...type slow. I understood this.

Thanks GS & alstick!!!

the DEF tank sensors are 100% solid state, just so everyone knows.

No moving sensor or "something to fail" like a fuel tank level sender.

ben

DEF when it freezes will be like a slush puppy everyones seen those.

The tank is heated ok the jello / slush could be and most likely is in the tube. Now based on where GM has there tube vs other mfrs the slush should begin to liquify as the engine compartment warms up. though with diesels that could take abit of driving.

The DEF is 67% water so it takes on more of the thermal chracteristics of water. It is a standard formula so its behavior wont vary. When you have your ND type winter days well then chances are you create some slush if the vehicle is stored outside. Again I think this will be less of an issue with GM than those who have all the components behind or under the cab. The theory is the fill tube should have been installed such that there is no pooling between the tank and the opening.

If there are any aftermarket ambulance builders out there better be sure this is a non issue before you start building fleet vehicles for local communities - not good

If I jsut spent 40-50-60-70K I appreciate all the greast feedback but frankly GM I dont need a Toyota type recall on my investment - I want a work truck that works PERIOD