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

[milkmaster]

11 hours ago, Byrds8 said:

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.

I admit to taking a little while to make it work including watching a youtube video.  Mine works as long as I have the HD icon on the screen active.  I looked up the local radio stations that have HD so I could test it.  I tune to an HD station and wait a few seconds.  Then an HD separate little icon will come up on the top left of the touchscreen.  Touch that icon and then it will indicate how many alternative channels exist.  Then you have to use the tuning arrows to go to the other choices.  Simply turning the right hand knob will NOT work.  Took me a little time to get used to it and not get run over at the same time.  You should know that some HD channels will show alternates even though they are not being used.  You can select them, but nothing may be broadcasting.   Maybe this will help.  I wondered if mine had HD radio as well being a chip shortage truck.  It does have it if you have the HD icon in your menu and on the radio screen.  Good luck!

Edited November 22, 2021 by milkmaster

[Byrds8]

46 minutes ago, milkmaster said:

I admit to taking a little while to make it work including watching a youtube video.  Mine works as long as I have the HD icon on the screen active.  I looked up the local radio stations that have HD so I could test it.  I tune to an HD station and wait a few seconds.  Then an HD separate little icon will come up on the top left of the touchscreen.  Touch that icon and then it will indicate how many alternative channels exist.  Then you have to use the tuning arrows to go to the other choices.  Simply turning the right hand knob will NOT work.  Took me a little time to get used to it and not get run over at the same time.  You should know that some HD channels will show alternates even though they are not being used.  You can select them, but nothing may be broadcasting.   Maybe this will help.  I wondered if mine had HD radio as well being a chip shortage truck.  It does have it if you have the HD icon in your menu and on the radio screen.  Good luck!

Thanks. Ill keep looking. However, even when I browse the stations, nothing shows up. I have it on the list of items they will be looking into. Have a great holiday.

[Sam Toteve]

Hi Everyone,

 

Newbie here as just purchased new 2022 Sierra 1500.  Just found out it has DFM.  Is there ANYTHING I can do to turn it off?  I see there are things you can plug in, but none say you can do it on 2022 5.3L - L84 - ECOTEC3 V8.  Atleast I don't have Autostop, but disappointed in this DFM thing.

 

Or am I worrying about nothing?

 

Sam

 

[Kilgore Trout]

On 12/17/2021 at 9:18 AM, Sam Toteve said:

Hi Everyone,

 

Newbie here as just purchased new 2022 Sierra 1500.  Just found out it has DFM.  Is there ANYTHING I can do to turn it off?  I see there are things you can plug in, but none say you can do it on 2022 5.3L - L84 - ECOTEC3 V8.  Atleast I don't have Autostop, but disappointed in this DFM thing.

 

Or am I worrying about nothing?

 

Sam

 

There is a device you can install that allows you to control some of the tuning parameters including DFM (thus, turn it off), it is called the Pulsar LT.  

 

The DFM lifter problem is contained to early 2021 MY trucks which had a bad batch of lifters installed (built before 3/5/2021).

 

I have a 2007 Yukon I bought new that was the first of the AFM engines.  It uses the same exact lifter design on my AFM system as the current DFM lifters.  When I first started reading Internet forums on these trucks, the "problem" with AFM lifters was a major topic. I became quite concerned that my 2007 "long in the tooth" AFM lifters in my Yukon were going to fail.  I asked my dealer service advisor, the same guy I have been using since I started going to that dealer and a VERY experienced guy on these trucks, if we should replace the AFM lifters in my truck as a preventative measure.  He said, "I have read about these AFM lifter failures, but we have never seen one in person (this is at a GMC dealer who is largest in the area in sales and service).  He said, "just keep maintaining your truck like you do and quit worrying about your AFM lifters".

 

Recently, he (like every GM dealer who sold these early MY 21 trucks), have now "seen" DFM lifter failures.  He had kind of a worst case scenario in that one of his fleet customers bought a batch of early 21 MY trucks and had multiple trucks go down with failed lifters.  Early on, they just replaced the bad lifter.  Then they realized some of the trucks were coming back with another failure, so they started replacing all 8 on the bank that had a failed lifter.  Then finally they realized if you have a failure of one of the lifters, you have a higher probability that another one will fail (of the originals installed when the engine was built) and it can just as easily be in the other bank as the original failure side, so now they replace all 16 lifters anytime they have the first one fail on any engine built in the bad lifter date range.

 

Personally, I am basically in the same boat as you in that I own a 2021 Sierra 1500 6.2L that was built later than the bad lifter cutoff date.  I considered the Pulsar LT, but have made peace with the notion that as long as I maintain my new Sierra, like I have my 2007 Yukon, I have about the same likelihood of a lifter failure as I have for the last 15 years of owning my Yukon.  I can live with that, so I quit worrying about DFM lifters.

[Cojam1]

I Currently have 2000 miles on my truck, it started tapping/ticking around 1700 miles.It's a a 2021 Sierra 4x4 X31 Without DFM. 5.3 w'8speed. Build date 10/21. Engine build date 9/21. Lifters making tapping sound intermittently,no codes. Have an appt. to bring in next week. Funny thing is it doesn't make the tapping/ticking noise all the time. My 2022 Camaro SS did the same thing at only 800 miles. Got the ALL the the lifters changed and traded it in for this truck. Maybe I should buy a lotto ticket. Lol

Edited April 9, 2022 by Cojam1
Correct spelling

[ThePearl]

Hey guys, New here as well. Just got a 2022 Silverado 1500 LTD 6.2L high country. One of the "Stop gap" models, my window sticker says no stop/start but it does indicate DFM is indeed on my truck. However, i have no indicator that i know of for it and i read on the gm authority site that ALL 22s won't have DFM. So now I'm super confused. I also have the Silverado EV reserved. Trying to determine to keep my 6.2 or trade when the EV gets delivered. If i can be one of the lucky ones to not have DFM issues, I'll likely keep my 6.2! Any thoughts on this? Advice? TIA

[John813]

6 minutes ago, ThePearl said:

Hey guys, New here as well. Just got a 2022 Silverado 1500 LTD 6.2L high country. One of the "Stop gap" models, my window sticker says no stop/start but it does indicate DFM is indeed on my truck. However, i have no indicator that i know of for it and i read on the gm authority site that ALL 22s won't have DFM. So now I'm super confused. I also have the Silverado EV reserved. Trying to determine to keep my 6.2 or trade when the EV gets delivered. If i can be one of the lucky ones to not have DFM issues, I'll likely keep my 6.2! Any thoughts on this? Advice? TIA

 

Yea it has DFM. My window sticker says the same thing. Could tell on highway when it would turn on. 

I've just been running the truck on L9 to disable it. I notice no real change in MPG. I could tell when the truck would drop cylinders on D/L10 but don't notice it on L9. 

 

For me if it fails, it fails. Figure after the warranty expires I'll rip all of the lifters/cams/dfm stuff and tune it to completely get rid of it. 

 

 

 

[ThePearl]

9 minutes ago, John813 said:

 

Yea it has DFM. My window sticker says the same thing. Could tell on highway when it would turn on. 

I've just been running the truck on L9 to disable it. I notice no real change in MPG. I could tell when the truck would drop cylinders on D/L10 but don't notice it on L9. 

 

For me if it fails, it fails. Figure after the warranty expires I'll rip all of the lifters/cams/dfm stuff and tune it to completely get rid of it. 

 

 

 

Gotcha! Thanks!! I'm not worried about it failing any time soon, more like 150k miles. If I'm gonna keep it, I'm gonna keep it that long. I get about 15mpg highway and about 21 mpg around town. And yes I'm on factory 22 wheels and tires. It's very weird. Even if i set the cruise at 70, and shut off AWD mode, no change. Are you experiencing anything similar?

[John813]

16 minutes ago, ThePearl said:

Gotcha! Thanks!! I'm not worried about it failing any time soon, more like 150k miles. If I'm gonna keep it, I'm gonna keep it that long. I get about 15mpg highway and about 21 mpg around town. And yes I'm on factory 22 wheels and tires. It's very weird. Even if i set the cruise at 70, and shut off AWD mode, no change. Are you experiencing anything similar?

 

For me, I get around 19 hwy(78-80 mpg) but my city driving is limited to stop and go so far so no concrete testing there. Flat highways in S. FL 

Z71 package with 20's and ATs. 

 

56 mile round trip with ~48 miles being highway. Still under 1k miles on truck so curious to see if it changes after it gets some miles on it. 

 

Same on length of ownership. I want to keep this long term and only the DFM is the thing that "spooks" me in terms of durability. 

 

 

 

 

Edited May 23, 2022 by John813

[WeGone]

2021 6.2 I was getting 18-20 around town and 23-24+ on the hiway, I added a Plusar LT to disable cylinder cancellation and only lost about 2 MPG  I love having a V8 full time.

[ThePearl]

 Awesome!! Thanks for the input! Maybe I'll have to do more testing on the Highway. We have a bunch of idiots around here that like to go 55 then 85 then immediately back down to 55 when you no longer have an opportunity to pass them lol thanks again! 

[Street Queen]

2022 LT TB Refresh 5.3 w/o DFM: I'm getting 14-17 around town.

[Samthebam]

On 6/8/2022 at 2:25 PM, Street Queen said:

2022 LT TB Refresh 5.3 w/o DFM: I'm getting 14-17 around town.

That’s worrisome.  Was considering the Range AFM disabler, but don’t want to adversely affect the gas mileage *that* much.

[Likarok]

So how many of you have had a afm lifter failure?

 

How many of you are using an afm disable program?

 

I guess I must have been not paying attention. But between the Transmission and now this lifter failure afm issue it sounds like I am sitting on a ticking time bomb with my 2017 6.2 High Country.

 

I don't really want to get rid of this truck since the new ones are so damned expensive.

[Jackseric]

51 minutes ago, Likarok said:

So how many of you have had a afm lifter failure?

 

How many of you are using an afm disable program?

 

I guess I must have been not paying attention. But between the Transmission and now this lifter failure afm issue it sounds like I am sitting on a ticking time bomb with my 2017 6.2 High Country.

 

I don't really want to get rid of this truck since the new ones are so damned expensive.

 

I have not had the issue. Only 14K miles, so time will tell.  *knocking on wood. lol.*