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  1. #1

    Default Do You Like Chevy's Active Fuel Management System? AFM Problems?

    I was wondering what the opinion of the group on GM active fuel management. Is this system reliable, it seems very complicated.? Could it be disconnected and the truck still run ie pulling a fuse or something.
    Obviously I don't understand the system so I look forward to your commrents

  2. #2
    TRPLXL2's Avatar
    Join Date
    Jan 2009
    Norwalk, Ohio
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    I don't know a thing about the active management system either, but I do know it switches from 8 cylinders down to 4 cylinders. My personal opinion is the dealership can't even fix a traditional fuel injection system, so how the hell are they going to keep up with this stuff. I have heard the speech a hundred times from the ASE certified technicians, "They send us to school all the time to keep up with all of the upcoming technology." Well how can you move on to rocket science when you haven't even completed biology, the concept of it is awesome but how does it really perform. Thank you for asking this question, I am curious about some of the answers that will pop up............AMY
    2004 Chevy Colorado
    LS1 5.7 swap/TBSS rear axle swap

  3. #3


    Yeah it seems you know about as much as I do. I was hoping with the fountain of knowledge on this site someone would jump in.

  4. #4

    Default Yikes

    No response, I'm shocked.
    I'm really just trying to find out if this is a reliable system. When the warranty runs out will you have to replace expensive solenoids. There must be somebody out there with this system on there trucks.

  5. #5


    I have the AFM on my truck. Ive had it over a year now and it seems to work flawlessly. I havent had any problems with it. If you drive on flat roads and highways, it'll will save you some MPGs. I live in a hilly area so it only cuts down to 4cyl mode when im on flat spots or coming down hill. Theres been several times ive done 70-75 mph on the freeway in 4cyl mode getting 36mpg. The changing from 4cyl to V8 mode is seemless there is no harsh bumping or jarring whenver it changes. I like mine, I could still live without it buts its just a lil bonus for me i

  6. #6
    Jr. Apprentice Dickie's Avatar
    Join Date
    Jan 2009
    Fresno, California, United States


    I have it on my truck havent had any problems with it yet knock on wood....Mine dont kick down to often with the way I drive

  7. #7

    Default One more

    Thanks for the replies. One more question, can you adjust the system or turn it on/off.


  8. #8


    I have an 08 GMC with afm. It gets 1 mpg better than my 94 Chevy did with the 350. Both Z71, 3.73, 4 speed auto. The 08 has 54k miles. The 94 had 212k. It will no doubt make engine work more expensive when the time comes, and from researching the net, it looks like afm causes some reliability problems. Google "afm lifter" or "afm oil consumption". Kinda scary. The only way of turning it off is a tuner. I don't trust it, but it seems to be the future. I once heard the quote "complexity is the enemy of reliability". Some truth to that, I imagine. The hemi has it also. And then there's the two turbos on the ecoboost. I'm not so sure the added technology is worth the added price tag, all in an effort to save fuel. Not sure how long you'd have to drive one to get that money back. And I have no doubt the added technology will cause some issues. Is a six speed auto more complex than a 4 speed? Yup. Are there more moving parts to fail? Yessir. Will it cost more to rebuild? Sure. I figure its the same way with an afm versus non afm engine. Now if I was getting 20 mpg, I'd say it was worth it. 16 mpg, not so much.

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