Why and How to Disable GM's Active Fuel Management (AFM)!

GM's Active Fuel Management (AFM) improves gas mileage by shutting down half of the cylinders under light-load conditions to reduce fuel consumption. It is also known as Displacement on Demand (DoD) or cylinder deactivation. Under certain conditions, it can help lead to 5-7 percent greater fuel-efficiency.

So why disable it?

Many people find the four-cylinder sound annoying if their vehicle is equipped with a louder aftermarket exhaust, and others want V8 power under their foot at all times. Also, AFM lifters have a history of failing and oil consumption can be a problem.

There are two ways to disable or delete Active Fuel Management on your GM or Chevy Gen IV LS or LS-based Vortec engine—one is to install an AFM Disabler, and the second is to install an AFM Delete Kit. We'll cover those options in this video and also show you how to identify AFM-equipped engines.

Items Featured in this Video:

[BarneeFife]

I have the feeling that GM decision makers can tell you where the best golf courses are, where to go for a 3 hour lunch, which people you need to cozy up to to keep your job, how to be a yes man or woman, but they don’t seem to know and/or care much about their product.
Thankfully there are guys like this within a computers reach. Thank you.

[SpynCycle]

I watch these AFM videos occasionally to reassure myself that sticking with my 2004 Avalanche is the right decision.

[rikkidietz]

Installed the Range Technology Disabler on my 2018 Silverado with the 5.3. Works great. No more bucking when going from 4-8 cylinders, more power. Lost 2 mpg on the highway. Highly recommend.

[truth]

This guy knows more about GM's engines than GM themselves.

[Motor-City-Mike]

Nice simple explanation and tempered to "soften" just how much trouble the system can create - simply put, several issues can trash an engine. Unfortunately the system and its unique parts are more complicated than needed to be explained and require diligent attention to maintenance to reduce the possibility of a failure.
Anyone researching just exactly how the entire system functions will find out just how mechanically "busy" the extra functions required are, and see all the areas for potential failure.
So far, mine ('07 5.3 Silverado) has functioned well, but is annoying. On flat level roads there's no sign when it is engaged except that because I have modified exhaust - the truck Sounds like it's missing. The annoying part is when the road is at all hilly and it's below expressway speeds. The system "hunts" turning on and off frequently, and the truck feels lazy going up a longer hill until the system Stays off.
Best to disable it and avoid possibly destroying an engine.

[undeadmonkey]

My new Chevy Silverado, 6.2L has this. Trying to gain and much knowledge as possible. Thank you for the info.

[rogernorgren]

Awesome job explaining this!!!
You should be in charge at GM because they don’t seem to know how this works themselves.
( failure of lifters on my 2021 Sierra with only 8.800 miles and they replace with same parts so just a matter of time I guess).
Anyways thanks again for the great explanation.

[waynebeasley]

I'm one of many who had the expensive experience of an AFM lifter failure on a low mileage engine. ( just out of warranty) The internal damage was extensive, and expensive. I didn't know about the delete kit until the rebuild was nearly complete……however I did buy an AFM disabler for my 6.2. My fuel mileage is exactly the same as before in mixed, city, and highway driving!

[FURDOG]

0:00 AFM. How to identify and disable.
1:50 Identifying AFM from non AFM engines.
2:20 Gen 4 and early Gen 5 engines.
2:54 2010 version improvements.
3:45 To disable.

[fishandgameman]

If you place the automatic transmission gear selector in the manual position and select the highest gear of 5 of a six speed, it will not go into AFM mode. Great for around town or hilly terrain. Kind of APITA to remember to do it each time but it works. Get on the open highway and let it go into AFM and save a little fuel.

[TheCowby]

I have a 2018 Z71 Silverado 1500 with the 5.3 and only 33, 987 miles on it. I bought it brand new.
My engine was ticking the other day. Took it to the dealership. Needs a new cam and lifters....
All covered under warranty FORTUNATELY, but I definitely ordered the disabler tonight and before I drive it off the dealership lot when it's fixed, I'll be plugging the disabler in.

AFM is not worth the trouble. I didn't buy a truck to get good gas mileage...

[jimmace]

As soon as I started getting lifter "tic" I installed a disabler. Within a few months the lifter noise became quieter and intermittent until it totally disappeared and has never came back after over 65k miles. I got lucky lol. But oddly I gained .6 mpg instead of losing mileage lol. Hardly noticable. But downshifts were definitely improved. But the 6L80E is still probably my least favorite transmission ever lol

[theconfused_fisherman]

Sounds like the Range Tech plugin is the way to go for my daily driver Silverado

[recyclespinning]

I had to turn in my leased 2017 Ram 1500. The dealer would not fix the cam phaser, check engine, dangerous limp mode issue. Was under warrenty, but the lease date was up. I returned it, luckily was leased .
I bought a pre AFM GMC Sierra 4x4, made in Canada, was a Texas truck, low miles. Great truck. I think these older trucks will go up in value. I'm starting to see it already.
I average 15 to 16mpg. Loaded with tools and ladder rack for work the four doors, I use the back for my portable tool boxes and very versatile . I can just put the tool boxes in the back bed and then I can carry 5 people. Comfortable on high way and town 😌

[divineoracle]

I was wondering if this was possible, I was in the market for a Chevy but when I heard about this issue I was sure to steer clear. What a STUPID DESIGN on their part. They are knowingly selling people a technology that destroys the car after warranty periods are up. Corporate greed, ohh well. I'll vote with my dollars. Thank you for supplying this fix for the people who already own one!

[texasfan]

Great video and very informative. This explains why some people still have lifter failure even after they've installed a disabler because it seems that the lifter or other components pertinent to the AFM/DFM system were already failing at that point. So in short, it might seem that the best solution is to purchase the disabler and install it almost immediately after you purchase the vehicle. This way, you are actually taking preventative action and not just putting a band-aid on an already bad part.

[mikef-gidg]

Now this info answers a lot of questions about gen 4 and 5 reliability and AFM DOD. I have the RANGE Dis-abler on my 2015 5.3 Silverado. I leave it plugged all the time. I'll take the hit on MPG, I didn't like the shudder I got when cruising at 30-45 mpg, converter locked up, in over drive, on 4cyl mode. The switching in and out of these systems, made me say, Oh Hell No. Disabled in v8 mode is smooth as expected. This system shifts thru all six speeds pretty quickly even in steady cruise, and the shutter wasn't going to cut it. Pulling a trailer with car, at 60 mph+ with AFM ENABLED, is no problem, and I get 20 mpg+. But I just leave it disabled.

[johnbehneman]

Great video and education. Thanks for sharing. I learned so much.

[TNtrailrider]

Great video! thanks for breaking this down and showing all options and when to used them for my truck.

[ちくてぬしくけて]

I like the look of the 2014-2018 silverados, but i think i'll be keeping my 2002 Chevy 2500HD.