Active Fuel Management (AFM) and Dynamic Fuel Management (DFM) will not be available on certain 2021 model year Silverado 1500/Sierra 1500 pickups

ratman6161 · August 9, 2021

On 8/1/2021 at 2:29 PM, Dave Felten said:

I recently purchased a 2021 RST with a 6.2 L 10spd. How do I verify if it has AFM/DFM or not? I don't see any display of deactivated cylinders on the drivers displays. I've read that certain engines were not equipped with AFM/DDM due to chip shortages, wondering if mine is missing that component or not. Thanks.

This will be specifically identified in the window sticker. Mine says "credit-not equipped with dynamic fuel. Management -$50"

Edited August 9, 2021 by ratman6161

remanaz · August 10, 2021

On 7/26/2021 at 6:32 AM, honkongphooey said:

I have been reading threads and articles on AFM - problems, performance, benefits etc and am leaning toward disabling AFM (NOT DELETE) and know about driving in L5 (mines a 2021 custom with 6 speed) to not engage cylinder deactivation. I tried an experiment where I drove 10 miles on highway at 65 in L5 and cruise on and got 20.2mpg at 2000rpm. I then drove same stretch in Drive at 65 with cruise control on at 1500rpm. got same mpg of 20.2. would have though there would be a difference. any ideas why not?

At that speed our trucks become to much of a brick in the wind for cylinder deactivation to activate it seems. Do the same at 45-50 and you should see a huge difference. I can see 26-28 at these speeds while only seeing 19-20 at 65.

Bignbald · September 2, 2021

Traded 2018 LT Silverado 2 weeks ago for 2021 trailboss custom without AFM!
oh what a glorious day!!!!! Fuel mileage is worse, compared to the 18 best I could figure, it is about 1 1/5 miles to the gallon But who freaking cares it’s a V8 24/7! Plus this truck just looks and feels better than the 2018!

Gary R · September 18, 2021

Hello

Does anyone know a way to determine if my vehicle actually has DFM ? (physically)

shakenfake · September 20, 2021

They all have the same lifters and camshaft so technically everyone has DFM. It should tell you when you go drop cylinders and the exhaust note will change.

Dirk13 · September 20, 2021

2 hours ago, shakenfake said:

They all have the same lifters and camshaft so technically everyone has DFM. It should tell you when you go drop cylinders and the exhaust note will change.

Don’t believe the new trucks have any indicator on the dash at all as you describe.

If you want to know if you have it scan the QR code in the drivers door and look to see if it has build code YK9. If it does, you do not have afm/dfm. If it does not, you do

shakenfake · September 20, 2021

Ah haven't drove a new truck so couldn't tell you. I just remember in my dad's K2XX Suburban it was like that

Jackseric · November 4, 2021

My 2021 Silverado HC has the 6.2L / 10spd combo and no AFM and no stop/start. Coming from a 2014 Sierra Denali with 5.3L 6spd, with AFM. This new one is incredible. Instant power and the drivetrain feels so much more solid and stable.

When looking at the new ones, the 6.2 window sticker shows better fuel economy than the 5.3... but I am definitely getting a little worse than the old truck did. Not much worse, but a little. I'm pretty sure it's because my new shoes are heavier than before... I can't seem to stay off that gas pedal.

Z45 · November 4, 2021

I just noticed 2 local GM dealers got an influx of trucks recently (over 20 between them, 21 and 22 models) and they all have DFM. What they don't have is Stop/Start.

haider320 · November 20, 2021

So, I've had my 21 SLT X31 for 3 weeks. Just looked at my build sheet and I do not have DFM. I also do not have the HD radio. Both show a 50.00 credit. So I'm assuming, with no DFM, I will not to have to worry about the lifters collapsing? Build date 10/21. I do have stop/start.

Edited November 20, 2021 by haider320

Byrds8 · November 20, 2021

1 hour ago, haider320 said:

So, I've had my 21 SLT X31 for 3 weeks. Just looked at my build sheet and I do not have DFM. I also do not have the HD radio. Both show a 50.00 credit. So I'm assuming, with no DFM, I will not to have to worry about the lifters collapsing? Build date 10/21. I do have stop/start.

I have had mine a week now. No DFM either. Although it shows I have HD Radio on the screen, I have yet to get it to work. My build date is 7/21 according to the sticker. Guess the dealership had this one laying around a while.

milkmaster · November 21, 2021

8 hours ago, Byrds8 said:

I have had mine a week now. No DFM either. Although it shows I have HD Radio on the screen, I have yet to get it to work. My build date is 7/21 according to the sticker. Guess the dealership had this one laying around a while.

mine built in June is the chip shortage truck too. I also have the HD radio , but I found it in settings where I had to turn it on.

Byrds8 · November 21, 2021

1 hour ago, milkmaster said:

mine built in June is the chip shortage truck too. I also have the HD radio , but I found it in settings where I had to turn it on.

The button on my screen turns mine on and off. Even looking through browse, it shows up no HD stations even though I know there are some in my area.

Edited November 21, 2021 by Byrds8

milkmaster · November 21, 2021

2 hours ago, Byrds8 said:

The button on my screen turns mine on and off. Even looking through browse, it shows up no HD stations even though I know there are some in my area.

Mine did the same until I turned it on in settings. The radio screen icon now goes to active when it is in HD. It didn't do that before when I thought it should. That's why I started looking in the settings menu. Maybe yours is different.

Byrds8 · November 21, 2021

Yeah I had gone out there and looked. If I turn it on in the settings the sound goes away just like touching the on screen button. Not sure what is going on with it but it is on my list of things when I take it in on Saturday.