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just curious why some people are choosing the disable the afm, with their tune? im sure if you have a truck with an exhaust system it must be annoying to hear it cutting in and out all the time on the hiway. other than that what benefit is there to it?

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I hope this thread doesn't turn into another afm war, but my main reason for disabling DoD (displacement on demand) was because of the V4 vibration and V8 re-start jerk that the dealer said was normal. Have tried turning it back on a few times over the past 3 years of ownership and I just cannot stand the way the truck drives with it on. I used Diablosport Predator handheld.

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I have the 6-speed which is the main reason I got a tune. I hated the way it shifted way to early around town under normal driving and then lugs and didn't want to downshift when needed. With the tune it has a longer hang time in each gear and builds a little more speed and RPM's (but not excessive) before shifting . I left the AFM turned on and now it goes into V4 mode more often and stay in V4 longer due to the increase in power from more RPM's. Often around town/suburbs I will be cruiseing at around 30 to 40 MPH. It will stay in 3rd or 4th gear at these speeds and switch to V4 mode. I can now gently accelerate or even pull a mild incline without it switching to V8. I have also seen a 1-2 MPG increase. I'm glad I left mine turned on but I have a stock exhaust.

Edited by RyanbabZ71

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I could never tell if mine was in v4 or v8 mode before adding my Corsa exhaust. I love my exhaust so may eventually turn afm off. The sound it makes while cruising in v4 with light throttle right before it goes into v8 is annoying.

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see ive never felt it transition between the two modes. its very smooth in my truck. i thought it may have had something to do with oil consumption issues and lifter noise and people were trying to fix them by shutting it off.

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FWIW, I drove my 2007 for 2.5 years and 45000 miles and never had any issue with the AFM, I would never know it was running in V4 unless I looked at the dash, Although I also had stock exhaust.

 

So instead of tuning the AFM out, I just bought a new truck without it! :thumbs:

Edited by hodo78

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FWIW, I drove my 2007 for 2.5 years and 45000 miles and never had any issue with the AFM, I would never know it was running in V4 unless I looked at the dash, Although I also had stock exhaust.

 

So instead of tuning the AFM out, I just bought a new truck without it! :thumbs:

 

 

 

 

^This.

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see ive never felt it transition between the two modes. its very smooth in my truck. i thought it may have had something to do with oil consumption issues and lifter noise and people were trying to fix them by shutting it off.

You would feel it with a tune and the stiffer transmission. I couldnt feel it before the tune but sure could after. It almost had a "buck" feel to it when it when in and out. Had to send the tune back to get the afm turned off.

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ive got an engine and trans tune in my truck, still cant feel it turning on and off. did a big stretch up the hiway the other day where it would come on and off during the trip and i didnt feel it a single time. maybe i just got lucky :)

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I have AFM on my 2011 5.3 and I hate it. I havn't had any issues with it, it works as gm designed it but unfortunately they designed it pretty poor. My 07 ram hemi had it and I didn't know until I sold it and dug out the window sticker, it was that smooth. This truck just plain sucks with it, it's jerky, noisy and causes my lifters to tick on start up. But dont worry guys, the GM tech said it's normal! Soon as i'm out of warranty either the AFM is gone or the truck is.

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I have AFM active of my tuned Tahoe. I can sometimes feel it but it is not harsh and I usually don't notice it unless I am watching the DIC and expecting it to switch modes. I'm not sure how a "stiffer transmission" would affect it as only the shift points are a little firmer. Maybe if you give it enough gas while in V4 and it downshifts at the same time it goes to V8 mode but I haven't noticed it. When I do notice it switching modes I don't mind because I know it is doing what it is supposed to do just like I don't mind feeling the transmission shift. JMO.

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I have 5.3 with AFM and notice it going from 4 to 8 and back and forth would even know it if it were not for the V4 indicator on the dash. I have only a few miles on it and hoping it stays that way.

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I just got my truck... but its a ticker and an oil burner... it was great for the first few thousand miles i had it but as soon as it started gettin cold the ticking at start up began. So I checked the oil, and it was down over 2 quarts in 5000 miles. Just did an AMS oil change today, hopefully that fixes the problem. If not it gives me an excuse to buy a 6.2 when the powertrain warranty is up :dunno:

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The trans is programmed to get to a high gear ASAP, I get around this by keeping the truck in M4 around town. No AFM, and much better throttle response. IMO there is no reason to be in 5th/6th gear at 35-45 mph.

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i havent seen mine go into 6th in the city ever, ill play in m mode and kick it to 5th to see if its in 6th and shes never been there. i notice a light tick in the cold weather, ive got another 95000 km of gm warranty on it, i wont check the oil because a new truck shouldnt use any. if i wanted to check my oil every time i filled up the truck id have bought a 15 year old truck. oh wait, my 1990 z71 with 311000 km on it didnt use any oil either in the old 350 :D

 

maybe a few of us are lucky, ive watched it go into v4 and ive tried to feel for it and she hasnt done anything to indicate shes gone into v4 mode. ill play with it some more tomorrow see if i can notice it with the colder weather coming.

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