DFM module for 2026

[lost1wing]

I installed mine (Range Technology DFM Disabler) today on my 25 Tahoe High Country 6.2L

Leaving wheel on but turning outward gives you room but I had 5 mini HEX trim screws to get out and then one bolt underneath. Its hard to get access to that module and detaching the OEM harness because fully extended you cant get much leverage. Taking wheel off would make it way easier.

One PRO TIP for those with the Advanced Security Package, when you disconnect NEG lead on main battery it sets off the piercing siren thats attached to the secondary battery thats hidden to power the Advanced Security Features. Scared the living Sh#! out of me and you cant disconnect that I know of.

I think truck runs better but could be placebo affect only time will tell.

I left the wheel on a straight. It would be easier to turn the wheel to the left, but not needed. 20 minute job not rushing it.

 

[sohanrd]

After some reading I’m going to buy this for my 2026 6.2.

Range website has them for $255 I was able to find it on Amazon for $230 and also 6% cash back with Amazon card. So $216 after the rebate. That’s the best deal I found on it.

Anything better?

Got mine from amazon too with amazon card. Dont think Amazon card gives you 6% cash back though.

 

[Marky Dissod]

Is there any alternative to the Range RA007? Or this is the only one?

Til you buy the Range, driving in L9 disables 10th gear and DFM.
If you notice a loss of 3MpG or more, hurry up and get the Range already; good news is you're extending the life of those weird@$$ lifters.
The sooner / more often you change oil and filter, the longer the engine will last, especially if you use 0w30 / 5w30 / 0w40 / 5w40.

 

[ReaperHWK]

Got mine from amazon too with amazon card. Dont think Amazon card gives you 6% cash back though.

If you chose delayed shipping with the Amazon card you’ll get 6%.

 

[ReaperHWK]

I left the wheel on a straight. It would be easier to turn the wheel to the left, but not needed. 20 minute job not rushing it.

Wasn’t bad. If you have air ride set it to max height and turn the wheel hard left. Also make sure you put the truck in service mode to lock the suspension height! You don’t want it to lower when you’re working down there.

I removed half of the wheel well liner becuase I didn’t want to bend it over the wheel like some videos I seen to prevent creasing it. I was able to have the wheel liner fall onto the tire straight down without bending it at all. Took longer but went well.

 

[Sgt1411]

Wasn’t bad. If you have air ride set it to max height and turn the wheel hard left. Also make sure you put the truck in service mode to lock the suspension height! You don’t want it to lower when you’re working down there.

I removed half of the wheel well liner becuase I didn’t want to bend it over the wheel like some videos I seen to prevent creasing it. I was able to have the wheel liner fall onto the tire straight down without bending it at all. Took longer but went well.

You can set the Air Suspension height to high level and turn the vehicle off and it stays up?...I had no idea you could do that, mine always discharges the system 2-3 times and lowers after turning vehicle off.

 

[ReaperHWK]

You can set the Air Suspension height to high level and turn the vehicle off and it stays up?...I had no idea you could do that, mine always discharges the system 2-3 times and lowers after turning vehicle off.

Yes.

1. Make sure the easy exit is off.
2. Set the height to max,it will tell you to select 4 low first though.
3. After height set, go to vehicle settings under suspension and set “service mode”. This will lock the suspension wherever it is if the car is on/off or whatever. The air ride icon on your dash will be yellow and indicate the suspension is locked. It will stay this way even with the neg battery disconnected, I did it.

This is on max height, it’s pretty tall.

 

[Jblaze31]

The Ranger DFM module will be my first mod on my Tahoe.

Does this void a warranty?

 

[2024 White Tahoe]

Does this void a warranty?

GM can void your warranty (such as new car, power train and emissions) if they discover it - but only for portions of the vehicle that the DFM module affects (such as your engine, electronics affecting the engine, etc.).

GM has sophisticated systems to detect the DFM module modification.

Some will argue that GM “has to prove the module caused a problem”. No they don’t. They simply have to detect the installed module and then deny your warranty coverage - which is placed in their nationwide computer system for any dealer to see. You must then fight the denial, which may involve going to court.

I would never chance it.

 

[Hey you]

I have had the Range installed on my 21 Tahoe with 90K miles now. Works great, no issues.

 

[Marky Dissod]

Does this void a warranty?

If one is dumb enough to leave it plugged in when they visit the dealer,
and the dealer and/or their mechs are not cool with you or the plug-in for whatever reason,
then the dealer/mechanic might snitch.

Shorter answer is to unplug it before visiting the dealer and lie about it if needed.
For govt-mandated emissions tests, unplug it one week before the test, and keep the fuel tank between 3/8 & 5/8 full for best results.
Pass the test, plug it back in.

 

[lost1wing]

Does this void a warranty?

2024 White Tahoe is correct. Even if they discover it, YOU can remove it and nothing may be said to affect your warranty. Especially if they want to ever sell you another vehicle.

If I was going to bring it in for an ECM update, I would remove it.

 

[Jblaze31]

GM can void your warranty (such as new car, power train and emissions) if they discover it - but only for portions of the vehicle that the DFM module affects (such as your engine, electronics affecting the engine, etc.).

GM has sophisticated systems to detect the DFM module modification.

Some will argue that GM “has to prove the module caused a problem”. No they don’t. They simply have to detect the installed module and then deny your warranty coverage - which is placed in their nationwide computer system for any dealer to see. You must then fight the denial, which may involve going to court.

I would never chance it.

So in my 2026 simply unplugging before oil changes wouldn’t do the trick ?

 

[Marky Dissod]

So in my 2026 simply unplugging before oil changes wouldn’t do the trick?

Is your mech a snitch-ass mark? If not, great!
If your mech is also a dealer, then by definition they are effectively both snitch ass marks AND who they are also snitching to. Think you'll figure it out.

 

[2024 White Tahoe]

So in my 2026 simply unplugging before oil changes wouldn’t do the trick ?

I am not sure, as I do not know if the module makes changes to the truck’s computer system (when activated).

Here is one GM TSB regarding aftermarket calibrations and changes: https://static.nhtsa.gov/odi/tsbs/2023/MC-10240359-0001.pdf

 

[lost1wing]

So in my 2026 simply unplugging before oil changes wouldn’t do the trick ?

It's not a simple unplug. Once you remove the module, the truck is back to stock status, with the exception of satisfactory evap relearn. This module is installed directly on the ecm port. The harness then piggybacked on the installed module.

 

[QwikKotaTx]

It's not a simple unplug. Once you remove the module, the truck is back to stock status, with the exception of satisfactory evap relearn. This module is installed directly on the ecm port. The harness then piggybacked on the installed module.

Can you clarify? Are you referring to fully removing it vs unplugging? The factory harness needs to be connected back to the ECM to drive either way.

 

[lost1wing]

You can't just unplug the module. You have to remove it. It's not a module that plugs into the obd2 port under the dash . It is mounted on the ecu that is located under the left front inner fender. You would need to unplug the harness from the module, unplug the module from the ecu an reinstall the harness on the ecu. 30 minutes is a generous amount of time to do this. But I wouldn't call it simple. Then you would need to drive it for a few days to set the readiness for evap emissions.

The issue is when or if you break down away from home, and it needs to be towed to a dealer, you now have a bit of a problem . You can keep the few tools needed for the removal in the truck. That is my recommendation.