Disabling GM Active Fuel Management

[East30]

Curious if anyone has disabled their AFM (Active Fuel Management) on their Chevy or GMC trucks. I purchased a 2021 Silverado during the chip shortage in the days of Covid chip shortages. I really liked that my Silverado did not have the AFM as they didn't have enough chips to activate it. Just bought a 2025 and now AFM is again enabled on all 5.3L engines and would like to disable it.

Wondering if anyone has tried this disabler: https://www.rangetechnology.com/products/afm-dfm_disabler/

I didn't seem to take a noticeable hit on mileage without the feature. I also had issue with previous Chevy's using oil with this feature enabled, as compression increases on those 4 cylinders, causing oil consumption as I was told by service technicians. Two previous Silverado's both used more oil. One, so much, that Chevrolet gave me a discount coupon to purchase a new Silverado. I would also feel much more vibration at stop, as it was idling on only four cylinders; stop lights and such. I don't notice that on my new 2025. Yet.

Thanks for any info that may be provided.

 

[TractorTYMe]

It should work ok, but the best would be to do an all out delete of the lifters and such to increase reliability. But I had a Pontiac G8GT with an L76 with this system, and I had it disabled in a tune. And it never gave me any oil consumption problems.

 

[deezler]

The range chips to disable AFM work very well. No issues. A couple of my coworkers routinely trade up through GMC/Chevy 5.3L 1500s and always buy the range chip to disable AFM/DFM.

If it were my truck..... I'd be doing an aftermarket ECU tune that increased HP and responsiveness as well.

 

[deezler]

I would also feel much more vibration at stop, as it was idling on only four cylinders; stop lights and such. I don't notice that on my new 2025. Yet.

I will say that GM vastly improved their cylinder deactivation strategy with their new DFM (dynamic fuel management). Instead of the same 4 cylinders turning off with the old AFM, the new DFM strategy continuously cycles through all 8 cylinder of the engine in as many as 17 different patterns, with anywhere from 2 to 8 cylinders running. But each individual cylinder never stays off for long, coming back on quickly to stay warm, keep the rings moving, avoid oil consumption issues, etc.

That said, it's a complexity adder who's only benefit is a 0.1 or maybe 0.5 mpg benefit. I would still disable it myself, but not as critical to do so vs the old AFM.

 

[Lineman North Florida]

I disabled it on a 2011 GMC Yukon that my wife used to have, when we got rid of it, it had over 250k miles on it with no issues, also disabled it on a 2012 Silverado 4x4 that I still own with over 200k on it and no problems, there is a cheaper one on Amazon than the Range and it does the same thing.

 

[ruffdog]

I have a Range disabler in my 2013 and it works fine. It will run the battery down if you don't drive much. You can get a extension wire for it that has an on/off switch. Most of my driving is local back roads so I shift into M5 which keeps it in v8 mode without using the Range.

 

[Hay Dude]

When did AFM start? My sons looking at a very clean, rust free 2006 5.3L with only 94K miles.
I thought it started 2007?

 

[Cub 7275]

Got two 5.3 with AFM. 2011 with 138K and a 2013 with 186K. I looked at the Range gizmo but there were complaints that it drained the battery if the vehicle is parked for extended periods, as mine can be. Just the fact that it draws that much power all the time (or keeps other modules from going to sleep causing the extra power draw) was a turnoff. A Diablo sport tuner was used to shut off the AFM on the 2013 because of the high mileage and not knowing its history with the previous owner(s). My main reason for disabling AFM was to prevent lifter failure where the lifter collapses when AFM is activated, but it doesn't pump back up when commanded to.

 

[Wolverinefarm22]

Free way to get around it is to put the gear selector in L and manually go to the highest gear. It disables afm or dfm and drives like normal.

 

[Cub 7275]

Maybe that works with the newer ones, but on a 2013, like ruffdog said, M5 will disable it. Select M6 and AFM is active. I believe the 2011 is the same.