DFM disabler released

[KMeloney]

I would say there is an improvement in acceleration and transmission smoothness, or at least not having the engine hunting and turning cyclinders back on during tip in throttle and acceleration. This then equates to less or no transmission hunting as well.

THIS is what I'd expect.

 

[Antonm]

Big difference between not firing the fuel injectors on decel (which is a good thing) and telling the lifters to collapse and not open the valves, which is what DFM does that the Range Tech device leaves on.
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[nick14226]

Just so everyone is aware, and Range did not have this info on their website in the description, when the Range 007 device is plugged in the Evap and O2 Sensor Emission Readiness Monitors will not become Ready. So if you live in an area that requires Emission Testing, you will need to remove the Range module for the Emission Readiness Monitors to fully become Ready prior to Emission Inspection, otherwise you will not pass an Emission Test. This is based on OBDII Emission Inspections.

I emailed Range and they confirmed this is the case, but again, nothing on their Website about the Readilness Monitors. Unclear if this will impact OBDII codes from triggering in the future, unclear if OnStar monitoring will pick this up. Based on the price point, this is clearly some form of Spoof module rather than a sophisticated microprocessor that alters the data stream the inhibit AFM.

So BEWARE, you WILL NEED TO REMOVE the Range device prior to Emission Testing.

Overall I am fairly happy with the performance of the module, but so far I only have about 300 miles using it.

Great info here @jfoj , thank you.

I had my OBD WiFi adapter going and thought everything looked normal as far as readiness tests last time I looked (with the range installed) but will check that out. Not a big deal to pull it though before NYS inspections.

Wonder if the carbyte uses the same technique.

 

[jfoj]

Reply from Range after I noticed issues with the Readiness Monitors on the Range 007.

[email protected]​	Tue, Nov 19, 2:58 PM (13 days ago)
to me

That is going to be normal. You would have to disconnect the module and do a drive cycle for the systems to show ready.

 

[nick14226]

No, not in an otherwise stock vehicle there isn't anyway. Our 6.2 High Country Tahoe didn't have any acceleration or transmission smoothness issues before the Range Tech device.

Before the Range Tech device, if you turned the radio off, and told the kids to be quite, you might, maybe, be able to tell when it deactivated cylinders if you tried real hard, and even then it was a maybe. I'm sure with an aftermarket exhaust it would be much more noticeable, but the stock exhaust is pretty dang quite.

And I agree with your last statement, it is a complete waste IMHO, unless you have a louder aftermarket exhaust, and the sound of the cylinder deactivation bothers you.

If Range Tech would make an actual DFM disabler (you know, something that just turns the dang DFM off, like how hard its that, just turn it off), then I would be first in line to get one.
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If you don’t notice DFM I would agree you’ll perceive it as a waste. If you do notice the vibration, hesitation, shudder, and all the other badness with DFM, I assure you you’d have the opposite impression.

Interesting to note, I’m driving a 2025 Silverado right now while my Tahoe is getting some warranty work done. For the first 500 miles or so it ran really nice. Peppy, didn’t notice DFM at all. It has 750 miles now and I’m starting to notice it. Its feel, not sound.

If one of us could figure out what variables are involved for those who say it’s undetectable versus those who can’t stand it, we’d be heroes.

 

[Kpwweb]

Why do you think the Range device will "potentially avoid lifter failure" when it still has the DFM functioning during the 0-Cylinder mode (which is literally every time you drive the vehicle and come to a stop)??? Having the 0-Cyilder part of DFM still enabled totally negates any potential lifter saving or reduced failure it might have.

Basically the one and only thing its good for is making consistent exhaust sounds for those with modified exhaust systems. Which I guess if that's something you care about then sure, the range tech device works fine.
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Because the lifters do not lock and unlock. They remain locked. You apparently have not had a lifter collapse and waited a month to get new parts. My lifters remain locked during decel—which the rest of my post stated. All 8 all the time.

 

[Scarey]

i have both range 007 and carbyte. I’m happy I have choices. Question is, and I asked on another thread, are these the only choices we have? It sounds like there is not an option for a tune on the, roughly 22 models on. Is this correct, no other choices?

 

[Antonm]

Because the lifters do not lock and unlock. They remain locked. You apparently have not had a lifter collapse and waited a month to get new parts. My lifters remain locked during decel—which the rest of my post stated. All 8 all the time.

But you’re wrong, you absolutely do not have all 8 all the time (lifters still unlock during decel). There is no special programming for the z71 compared to any other model.

The reason you feel the slow down is because the DFM is unlocking and collapsing the lifters on deceleration. If the lifters were to remain locked the effective deceleration would be lessened.

This change in the way the vehicle feels to the driver is why Range tech left that part on, because they assumed most of their customers are stupid and would complain about the change in the driving experience. So they completely negated the primary reason most people want a DFM disabled in the first place.
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[Kpwweb]

But you’re wrong, you absolutely do not have all 8 all the time. There is no special programming for the z71 compared to any other model.

The reason you feel the slow down is because the DFM is unlocking and collapsing the lifters on deceleration. If the lifters were to remain locked the effective deceleration would be lessened.

This change in the way the vehicle feels to the driver is why Range tech left that part on, because they assumed most of their customers are stupid and would complain about the change in the driving experience. So they completely negated the primary reason most people want a DFM disabled in the first place.
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If that is the case, then deceleration would be the same with or without the Range. It is markedly not. Deceleration is demonstrably greater with the Range than without. As Range stated, “some customers will have…”

Why the difference with some and not others?

 

[Antonm]

If that is the case, then deceleration would be the same with or without the Range. It is markedly not. Deceleration is demonstrably greater with the Range than without. As Range stated, “some customers will have…”

Why the difference with some and not others?

So let me get this straight,,,you think that a piston going to the top of the cylinder with an open exhaust valve every other engine rotation, which will allow the air/gasses in the cylinder to escape out the exhaust system, will provide the same resistance as having both valves closed (because DFM collapsed the lifters) so that every time the piston goes to the top of the cylinder it must compress those gases? Do I have that right?

In a V8, in any given rotation of the crankshaft, with the lifters locked, there would be four cylinders doing a compression stroke and four cylinders on an exhaust stroke when the piston came to the top of the cylinder, so only four of the cylinders would be causing resistance to rotation, or braking force, for every crankshaft rotation. Now unlock the lifters, and all eight cylinders would be compressing air/ gases causes resistance to rotation, or braking force, every time they came to the top of the cylinder.

The whole restricting the exhaust thing is the same principle (different method, but same principle) used the ever popular "Jake Brake" on diesels, seems to help slow them down.
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[Antonm]

Post edit:
Looks like Holley (Range Technology is one of Holley's brands) got bought by one of those investment firms/ capital groups (Sentinel Capital Partners in this case) back in 2018.

When that happens it usually means the downfall of the company and it products because the focus goes from making a quality product, to making money. Because the investment company guys aren't car guys, they're money guys.
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[fondupot]

FWIW, I haven't noticed any difference in deceleration since installing the Range module. Is the 0-cylinder decel/coast feature really activating DFM lifters to close off valves? or is it simply cutting off fuel supply to those cylinders? Big difference I should say.

 

[Kpwweb]

So let me get this straight,,,you think that a piston going to the top of the cylinder with an open exhaust valve every other engine rotation, which will allow the air/gasses in the cylinder to escape out the exhaust system, will provide the same resistance as having both valves closed (because DFM collapsed the lifters) so that every time the piston goes to the top of the cylinder it must compress those gases? Do I have that right?

In a V8, in any given rotation of the crankshaft, with the lifters locked, there would be four cylinders doing a compression stroke and four cylinders on an exhaust stroke when the piston came to the top of the cylinder, so only four of the cylinders would be causing resistance to rotation, or braking force, for every crankshaft rotation. Now unlock the lifters, and all eight cylinders would be compressing air/ gases causes resistance to rotation, or braking force, every time they came to the top of the cylinder.

The whole restricting the exhaust thing is the same principle (different method, but same principle) used the ever popular "Jake Brake" on diesels, seems to help slow them down.
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Obviously everything you say depends on cam timing, temperatures, air in the cylinders, etc. But I’m not as “smart” as you are.

The thing is, you will believe what you believe, I will believe what I believe. The Range gives me a small glimmer of hope to modify my vehicle without resorting to a full tune—especially since GM has locked down the ECM. My last Tahoe I had tuned and got 125k out of before trading it on this one. Dealership still got $25k for it. It was glorious.

Even if DFM is turned off half the time, which we can debate until the end of time, that would still equate to longer life than having DFM engaged all the time. I’ll take that opportunity as a “dumb” consumer. You can tool around in your DFM rig, its a free country. Most people don’t notice. I do.

I do wish someone would come out with a tunable piggyback unit—it just might be you? You could be the driving force for good, right to repair…..

 

[Antonm]

Even if DFM is turned off half the time, which we can debate until the end of time, that would still equate to longer life than having DFM engaged all the time.

While never having cylinder deactivation would be the best, I suppose having less of it is at least somewhat better.

Still wonder why they wouldn’t ( maybe couldn’t) just turn the whole dang system off, they even named the device “DFM disabler”

Holley ( the parent company of Range Tech) sent me an email listing all the hoops I needed to jump through to return the device , things like “must be in the original packaging” was in there, a restocking fee and it has to pass their inspection before they’ll consider refunding ( of course if it doesn’t pass their inspection then you’re just SOL).

I posted screenshots of the emails but edited the post because it didn’t matter, then I looked closer and figured out Holley isn’t a car enthusiast company anymore, they’re owned by an investment capital company, so car guys no longer make the decisions, money guys do, so it makes sense that they’re making crap products now.
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[Marky Dissod]

Please bear with me for a few stops on a train of thought ...

Maybe back when GM's Gen4 V8s first debuted, 'disabling' cylinder (valve) deactivation was easy and simple: deselect what tuners call a 'switch' / 'flag'.
The most basic tuning experience (after switches and flags) involves changing temps / RpMs / road speeds / throttle %age / MAP reading
so that, even if a feature's switch / flag remains 'enabled' - or is simply unavailable! -
by specifying an unlikely or impossible temp / RpM / road speed / MAP reading, or an impossible combination of those,
a feature can remain enabled and yet still never activate.

Example: by raising the 'CAGS Enable' coolant temp threshold over 125C / 257F, that T56 will never force a 1st-to-4th ever again.
If something odd happens to the coolant temp circuit,
change the 'Speed Threshold to Disable CAGS' to 1MpH (or 155MpH), then
change the 'Speed Threshold to Enable CAGS' to 0MpH (or 154MpH), and CAGS is effectively disabled.

Two more stops ...

 

[Marky Dissod]

Some of you know that the plug-ins that disable auto-stop start and or cylinder valve deactivation
are not tunes-in-a-can; rather, they fool the ecm, either by feeding it false info, or hiding something from the ecm.
Since several conditions (temps / RpMs / road speeds / throttle %age / MAP reading) have to be met for cylinder deactivation to be allowed,
and ALL of them must be in effect (each within a narrow permissible window) at once for cylinder deactivation to be active,
if any one of them is missing or false, the ecm will not activate cylinder deactivation even if it is enabled.

 

[Marky Dissod]

I've only seen a GM Gen5 V8's tunable parameters once, and that was before 2017,
when GM started using much more complex encryptions (that's why it takes a few years to 'crack' an ecm / tcm;
ifyouarenotfluentinalanguageit'snoteasytodecipherwherewordsbeginandendandthat'safterdefeatingtheencryptions -
oh and ecm / tcm code is written in hexadecimal).
It is increasingly possible that there are more parameters that enable and/or activate cylinder deactivation,
or worse yet, some combination of more parameters ...

In other words, I'm not shocked that disabling cylinder deactivation is - for the time being -
impossible until the vehicle gets over 40MpH, or that it cannot be completely disabled when the TPS% = 0.

 

[Scarey]

So does this mean there is no tune available for the latest generation Dfm? If so, can it be deleted, cam, lifters, etc.?

 

[Antonm]

So is that a general consensus then that Range Technology DFM disabler does not actually disable the DFM, but modifies how DFM operates and certain parts of DFM will continue to be fully functional even with it installed then?

If so that's good information to have here (and anywhere else around the internet) so potential future buyers know what they are , and what they are not, getting when they buy one of these devices.
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[fondupot]

So does this mean there is no tune available for the latest generation Dfm? If so, can it be deleted, cam, lifters, etc.?

I got a quote from Trifecta Tuning to tune out DFM via a custom tune. It's not something they advertise on their website, but I inquired with them because I had a tune from them on my 2019 GMC Canyon LGZ V6.

They quoted me $1800, and I would have to physically remove the ECM from the truck and send it to them for tuning. I passed on that obviously. And just went with the Range unit.

I would love to just throw a bunch of money at this truck and delete the mechanical components associated with DFM, but its just not feasible at this point in time. Range unit will suffice for the time being.