Disabling GM Active Fuel Management

[riptides]

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?

https://www.silveradosierra.com/threads/what-year-was-afm-introduced-into-silverado-sierras.659041/

 

[East30]

Update, I did find that the disabler I posted at the start does not work on the 2025 Silverado I purchased.

I would need this one: https://www.rangetechnology.com/products/afm-dfm_disabler/parts/RA007
It's new. I called and they stated it was just finished testing in the last couple of weeks. So it's really new.

It has a bonus in that it also disables the auto start/stop feature, which I've always disliked.

 

[dodge man]

My opinion on AFM relates to how it works on Chrysler products. Hemi engines have had it for several years on cars and trucks both. They call it MDS, multi displacement system. It does work well for saving fuel but much better in cars than trucks. I’ve got a 2010 Challenger that I turned it off on. I’ve had a truck that had it also and we have a 2019 Chrysler 300c that has it.

Programming has a lot to do it. Our newer 300c is so much better. It isn’t constantly trying to go into 4 cylinder mode and as you approach 75mph it just stays running on 8 cylinders. On the Ram we had, a 2007 I think, it just cut so much wind on the highway it was constantly trying to switch in and out of 4 cylinder mode.

On my Challenger the programming was so annoying, it was just constantly switching on and off. When I turned it off I was shocked how much it affected fuel mileage. I’d say it was at least 10% worse. It’s a 15 year old car with 24,000 miles on it so the hit on mpg is meaningless to me.

 

[TheGoose]

I have the range for 2018 vintage Silverados and it works as advertised. Never noticed a drop in mileage , actually think it got slightly better if anything.

 

[5030]

Disabling the GM AFM entirely depends on the year of manufacture actually. Some can be done with an add on module, some have to be mechanically deleted. All BS as far as I'm concerned and all contribute to burning oil from dried out cylinders.

 

[ruffdog]

Disabling the GM AFM entirely depends on the year of manufacture actually. Some can be done with an add on module, some have to be mechanically deleted. All BS as far as I'm concerned and all contribute to burning oil from dried out cylinders.

The oil burning was not caused by dried out cylinders. The problem was too much oil being sprayed at the piston skirts from the AFM pressure relief valve. Too much oil then would overload the oil control rings and create problems with the PCV system. Both would lead to oil consumption. Those issues were addressed in ~2011. They relocated the pressure relief valve, installed a shield, changed the valve cover design (PCV).

 

[5030]

The oil burning was not caused by dried out cylinders. The problem was too much oil being sprayed at the piston skirts from the AFM pressure relief valve. Too much oil then would overload the oil control rings and create problems with the PCV system. Both would lead to oil consumption. Those issues were addressed in ~2011. They relocated the pressure relief valve, installed a shield, changed the valve cover design (PCV).

Whatever. All I know is my wife's 2016 Suburban LTZ was using oil at rate of a quart every 500 miles and I did the mechanical delete on it and the oil consumption immediately stopped and her overall fuel mileage (not that it was ever good) didn't change a bit.

The ONLY reason why GM did it as to increase their CAFE to comply with the gummit.

Early models can be deleted electronically but some cannot. All depends on the year, displacement and how good you are at being a shadetree mechanic.

Now, other than normal oil consumption ( all internal combustion engines consume a bit of lube oil), it stays full or close to full between oil changes.

...and the oil and filter gets changed every 5, not 10 and it gets my usual Nano Borate additive as well at a rate of 1 fluid ounce per quart of oil.