user fuel state derate?

[Kryptic361]

(05-13-2021 )Chamberpains Wrote:  Your truck can be tuned for a fixed vein turbo. You just need to upload your current calibration and get it sent off to Rawze. He may guide you on what needs to be done.

You say control box are you referring to the actuator on the turbo? Here's a question. Did the actuator mount on the side of the turbo and have an air line attached or was it mounted on top and had electrical wires going in to it? I ask to make sure what beast we're actually dealing with. The cm870 had an air actuated turbo and the cm871 had electric.

It was air actuated the control box on the driver side of the block had the plastic base and the twxh at the dealership over a year ago when they put that box on screwed up the threads. The truck is an early production 07 with an 06 cm870 in it from the factory.

[Rawze]

You need to get that VGT back on it. I suggest you fix whatever stripped threads there are and get it back right.

- You obviously have been dealing with a bunch of clueless people for even suggesting you take off that turbo.

Your welcome to send me a copy of the program out of it, I will review it and tell you whats in there ... but the engine will never be right unless you put that the VG back on it the way it is supposed to be.

- IT IS ONLY THOSE BAD DELETE COMPANIES THAT REMOVE THOSE VG Turbos because they do not know how to program it correctly for a de-mandate ... Then they tell you anything they can and make all kinds of excuses to sell you their aftermarket garbage instead.

The issue you described (before the VG was yanked off it by mistake) sounds exactly like the all too familiar silent emissions derate from the ecm that CM870's are notorious for. It will spike to about 34-36 psi ... then drop back to about 22-24psi, mayby 29~ish, or sometimes to 32-psi, depends on severity .. or so and hang there. That model engine has been around for more than 18+ YEARS NOW!!!! .. and this is a very well known issue actually. The people your dealing with are obviously completely clueless if they do not know this about them already. They should NOT BE DIGGING AROUND inside your ecm programming and settings if they don't know what the he$ll they are doing or what they are dealing with... and what you described sounds exactly like this well known issue that happens to them once the EGR stops working for any reason.

I have seen it a hundred times in the past on CM870's ... and the irony is that most delete shops have no clue how to get rid of this issue ... because they don't even know how check it, nonetheless how to make corrections. What they resort to instead of using a proper solution (because they have no idea what they are looking at in most of the programming any ways), is that they are quick to trying to get the truck owner to yank off the VG turbo off because they donl't know how to control or re-program it properly at all, and especially for a proper de-mandate. That is truly how utterly clueless most these guys really are. They can jail-break the codes from showing up in the dash real good ... but trying to get the engine to run right after is a joke!.

.. when the engine does this, instead of solving it, they resort to try to add fuel into the cylinders against the ecm's will, they edit the H#ell out of the ecm program, poking and screwing and try every trick to overcome this ghost problem that they are clueless against.

The Irony and reason is that most those (clueless ) "tuning experts" don't even know where to start ... nonetheless will realize that the issue is not even in the programming itself...

THE AUXILIARY EMISSIONS AND SILENT DERATE LOGIC IS LOCATED IN THE RAM MEMORY OF THE ECM ITSELF AND NOT ACTUALLY THE PROGRAMMING on the CM870 and CM875 engine ecms. - You can flash a thousand different style programs in there and turn off anything you want in them... but it will not fix a damn thing towards this.

The CM870 and CM875 ecm's are unique with this requirement of having to edit the ram memory itself to properly shut off the Aux. emissions and the silent penalties that make the turbo, power, etc. fall back like that. - How much you want to bet that if you go ask the so-called-guru what ram memory settings and addresses that need correcting that are located "not in the program itself, but can only be accessed live in the ecm" ./.. your going to get an argument instead ... Likely get mad at you for suddenly knowing more than they do about it.

This is as old as the CM870 have been around... and you'de think that after 18+ years of people tweaking on them that they would know this about them... but more than 99% of these clowns are beyond clueless... and would not know where to begin. the irony is that the clowns who hang out on all the engine tuning forums and sites are the biggest offenders of not knowing how to properly control these engines.

BTW: Switching the programming from one ecm to another and slapping it on will simply trigger it in the new ecm right away and nothing will change towards this.


NEXT: What engine operating mode is it running in?. For the CM870 they are ...

- engine cranking mode.
- Cold enigne warm-up / over-load protection
- EGR + low altitude mode.
- EGR + high altitude mode.
- EGR + Extreme altitude mode.
- The built-in Factory-programmed no-egr operating mode.

The Auxiliary. emissions (sometimes known as off-road emissions control) and silent boost derate will normally kick in no matter what engine mode your in if there is an egr issue.

-- For all you know, some moron may have programmed it into using high altitude mode, or it could be in a perpetual overload protection state all the time. Matter of fact, I saw one the other day permanently stuck in overload protection... or worse yet (and more common) ... someone never touched the engine mode control logic at all because they had no clue what they were doing, and assumed the ecm had some kind of magic fairy dust inside it to know what to do ... and instead, it is using one or more of its EGR + modes all the time.

here is a screenshot with all the settings in Calterm that need to be monitored, so that the exact engine state, what operating mode, what emissions systems are in control, etc.etc.etc. are happening live in the ecm ...
http://rawze.com/forums/showthread.php?t...3#pid58693

make a screen file just like this WITH ALL THE SETTINGS, DON'T SKIP ANY and record your desktop while on a test drive... send me the video of it and I will analyze all the data and tell you exactly what that engine doing, is=ts mode, its systems, what is making or holding back the fuel, and why...etc.etc.etc.


- Some well known issues sounds to me like may be a big part of your problem but that is just speculation. Someone must keep in mind that low boost and other power issues are not always simply programming itself.


- My suggestion is that you Put the VG turbo back on it and then take the ecm to a stealer#shi#t and have the exact latest factory program flashed back into the ecm that belongs to the truck and engine. Then solve any and all fault codes that are not related directly related to the egr valve itself being unplugged. Get that engine back to a state where it will drive right, it will boost up, and falls back like it did before, and at least drives somewhat normal again. CM870's will not shut down with factory programming if the egr is unplugged. Many people drive them like that for a million miles + without issues, perpetually in a boost derate (though it is not the best thing for them).

- After that, if ya want to keep it de-mandated and rid the engine of its derate, then correct the program for it and fix the RAM memory aux. emissions live in the ecm. BOTH proper programming AND editing the ecm live properly to operate the engine AND VG TURBO are needed safe, full power and torque no-egr operations (assuming you live in a country where that stuff is legal). - This is your road to a proper recovery. Anything less and you will just continue to have problems and get ripped off by clowns who are clueless.

- There are ways to do things right, so that a proper and predictable outcome is achieved. You simply have to "do them right".

Forum member 'running rough' is the resident forum member that deals specifically with CM870's and all of their quirks with people. Give him a PM message and see how he can help you.

[Kryptic361]

Thanks Rawze. I do have insite and calterm. And have pretty much given up on this "tuner" . i will plan in putting the VG back on.

I can program the factory most recent CAL for my calibration from cummins in it pretty easily.

I found some of the Ram setting while digging around in a spare ECM i have hooked up to my bench harness. But haven't got to deep into trying to modify any of them cause thats beyond my level and dont wanna kill this truck.


I am by no means a tuner. And the only tuning i do is on my personal pick up truck to get the power/ fuel mileage out of it while keeping it clean and pulling my 5th wheel around the country.

I cant get thr video this week ( out in the rental truck) but i can get it for you next weekend for sure.

Once again. Thank you. And ill get you the info you need as soon as I get back from the road.