GM Active and Dynamic Fuel management lifter issue.

[Logical Guy]

I bought a brand new 2021 Silverado 5.3L with D.F.M around 05/2021 and in January of 2022 I started hearing more and more about the lifter issues the 5.3L, 6.0L and 6.2L were getting. So I looked around on the web and saw there is a class action lawsuit with GM about this. The lawsuit said that GM will upgrade the lifters before selling the new 2021 models on their lots. So I called the dealership I got mine from to ask weather mine was done. They said they will look into it and call me back. The salesman called me back the next morning and told me they entered my vin # into their database and said mine does not show that any work was done or that any work needs to be done. I asked if I must just drive it till something goes wrong and they basically said unless there is a recall there is nothing they can do. There are 2 popular methods out there for disabling the A.F.M and D.F.M but I don't know if I want to mess with that. Your experience and thoughts are appreciated.

[dgstarr63]

I am using the Range. It plugs in under the dash into the diagnostic connector. It can be easily removed for trips to the dealer. I leaves no record on the computer that it was there. You will still  have the weak valve lifters, but I believe you will less likely to have a failure if the lifters stay in the locked position.  This is no guarantee, but worth the effort to reduce the issues with this poorly designed system.  All AFM/DFM trucks have weak lifters, but ones built from 9/20 - 3/21 are worse because of a possible defect in an already inferior system.

[2016 Sierra Owner]

On 2/12/2022 at 12:28 PM, Logical Guy said:

I bought a brand new 2021 Silverado 5.3L with D.F.M around 05/2021 and in January of 2022 I started hearing more and more about the lifter issues the 5.3L, 6.0L and 6.2L were getting. So I looked around on the web and saw there is a class action lawsuit with GM about this. The lawsuit said that GM will upgrade the lifters before selling the new 2021 models on their lots. So I called the dealership I got mine from to ask weather mine was done. They said they will look into it and call me back. The salesman called me back the next morning and told me they entered my vin # into their database and said mine does not show that any work was done or that any work needs to be done. I asked if I must just drive it till something goes wrong and they basically said unless there is a recall there is nothing they can do. There are 2 popular methods out there for disabling the A.F.M and D.F.M but I don't know if I want to mess with that. Your experience and thoughts are appreciated.

Don't look for any relief on the class action suit. They have had at least 1 (maybe more) for the 8 speed transmission that didn't get anywhere.

[WeGone]

Using the Pulsar LT, Love driving a V8 full time and I don't have to give up 10th gear (running one gear under your top gear is said to be the free way to keep it disabled). I like that it also turns off the Auto/Stop. I did lose a bit of MPG, but I bought a 6.2 for the HP not the MPG. 

[Joedert]

Does the Range require a computer to to download anything before you hook it up? Because I don’t own one.

[WeGone]

On 2/15/2022 at 6:41 PM, Joedert said:

Does the Range require a computer to to download anything before you hook it up? Because I don’t own one.

 No. Plug and Play.  And for the record I have received over the air updates while the Pulsar LT was installed with no issues.