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2014+ AFM (Active Fuel Management)

Ron.s

By Ron.s
in Engines & Drivetrain

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Joe_K Enthusiast

Joe_K

Posted
Posted

 

Same here by last vehicle had MDS (Hemi) and I did not notice it switching either but it did not have any lights or anything to indicate that it was switching between the two separate displacements.

 

Strange, I could definitely tell when the MDS kicked in on my Hemi. Then I cut the factory muffler off and put a 14" Magnaflow on it, after that the MDS drone was horrible so I turned it off with a tuner.

 

fea87f68-6b8a-4798-b6a7-6b8361706115_zps29e272ae.jpg

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oldmann
oldmann

Why are people so concerned about this topic. I do not understand it. Just drive it. End of story. And yes, even if you can't figure out why the truck has it, it is to save fuel.

pm26
pm26

No, it does not. Not even close. The only Cadillacs that possibly exceeded the weight of 2014 GM crew cab 1500 4x4 pickups were the old land yachts (1976 and older) models. I believe that a 1976 Ca

seamonster
seamonster

Whats up with the name calling?   Cant you see we agree----the AFM feels like a gear shift!   Many people want 6 and 8 speed tranny and then complain they can feel AFM. That is what I dont unders

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voltedge Enthusiast

voltedge

Posted
Posted

Same deal here. My old Ram Hemi felt like a harsh downshift and the obvious rpm engine sound change. This truck does it as well. but it's so smooth that you only notice it if you are in an area where it does it back and forth from 4 to 8 a couple times due to whoop de do hills on the road. The transmission shifts so much smoother than my old Ram, that I believe it takes care of most of this. I will say that I feel like it is a little harsher now than when it had less than say 1,000 miles on it.

KUUG Enthusiast

KUUG

Posted
Posted

Mr Kugg

From the look of your truck with lift and tires not getting V4 very often is not a problem, it should be expected.

 

Of course its a problem! There only 33's. The better gas mileage I can get the more my wallet likes me.

 

I do realize that bigger tires+lift = bad mpg but I didn't go that big. It's expected but I took a pretty drastic hit on highway mpg. Either way I like the truck how it is now so nothing is going to change.

dkeven Enthusiast

dkeven

Posted
Posted

mine switches out fairly seamlessly now with 7800 miles on it, lower
speeds seem to make it more noticable. Can't give it to much gas without
it going back to V8 mode do it stays in V8 most of the time. Mileage is
a little better than my other trucks were and if I try will get a lot
better but fun suffers than.

JCthebigTree Enthusiast

JCthebigTree

Posted
Posted

Almost, but not quite, as perfectly seemless as my '07 Yukon.

 

Only thing is, when paying attention on a long (9 hour) highway drive, it barely ever kicks in on mine...unlike some, I'd like it to improve my mpg. Basically had to get on a long downhill for it to kick in, on m '07 Yukon it would kick in on every flat stretch.


Seems like it get back into V8 the instant I need it too...so no real complaints.

reldridg Enthusiast

reldridg

Posted
Posted

Strange, I could definitely tell when the MDS kicked in on my Hemi. Then I cut the factory muffler off and put a 14" Magnaflow on it, after that the MDS drone was horrible so I turned it off with a tuner.

I could probably not tell when it kicked in on my hemi motor because it probably never did. The fuel mileage on that engine was amazing I could get almost 10mpg and I drove it like a granny. What was even better was that it had about a 17-18 gallon tank so I could almost get far enough away from the house so that I could not walk back and get a gas can when it ran out of gas.

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bearman95 Enthusiast

bearman95

Posted
Posted

The only way I notice the switch is if I watch the read out on the dash. Its this way on both of my trucks. Very smooth and quiet.

2014big3 Enthusiast

2014big3

Posted
Posted

Of course its a problem! There only 33's. The better gas mileage I can get the more my wallet likes me.

 

I do realize that bigger tires+lift = bad mpg but I didn't go that big. It's expected but I took a pretty drastic hit on highway mpg. Either way I like the truck how it is now so nothing is going to change.

KUGG Naive is the problem. The V4 has no chance with your mods. It was designed first and foremost to fool the EPA with their indoor dyno ( no wind ) low speed testing. You fell on the wrong side of the razor's edge that it works on in real life flat hi way when you modified.

KUUG Enthusiast

KUUG

Posted
Posted

KUGG Naive is the problem. The V4 has no chance with your mods. It was designed first and foremost to fool the EPA with their indoor dyno ( no wind ) low speed testing. You fell on the wrong side of the razor's edge that it works on in real life flat hi way when you modified.

 

I guess if your going to start talking trash online you should first get the name right!

Designed indoor or outdoor I really don't care and that has nothing to do with my statements. But that's about all the conversation I will have with you; you're obviously not following anything I said.

mike94silverado Senior Enthusiast

mike94silverado

Posted
Posted

I drove 2 14's overnight while making the decision whether or not to buy one and it was seamless. to tell you the truth, It is in my 2010 too, and I have an insight monitor that shows it kicking on and off and you can't feel anything..... Maybe I got a defective truck? lol

TechSTL Enthusiast

TechSTL

Posted
Posted

I could probably not tell when it kicked in on my hemi motor because it probably never did. The fuel mileage on that engine was amazing I could get almost 10mpg and I drove it like a granny. What was even better was that it had about a 17-18 gallon tank so I could almost get far enough away from the house so that I could not walk back and get a gas can when it ran out of gas.

 

:rollin:

 

As someone else mentioned, the slower you're going, the more pronounced it its. On the highway at 60-70 mph, I don't feel it at all. I have a 5.3 with 3.42s.

 

At slow speeds, it feels like a shift.

bboyce536 Enthusiast

bboyce536

Posted
Posted

First time poster, but long time browser...

 

I definitely notice the switching between modes and unlike others, I seem to notice it more as the speed increases. It almost seems like my truck is trying to stay in V4 mode longer then it should..for example, on a small uphill I will start to put my foot in the throttle to keep my speed and it will stay in V4 so I keep pressing the gas and then it feels like it downshifts as it finally switches into V8 mode. Not sure if that's normal or not but it does bug me. This is my first GM with AFM...Kinda makes me miss my old 2011.

Stex Senior Enthusiast

Stex

Posted
Posted

'09, cannot tell if not for DIC. tested 2 14s cannot tell at any speed. I think you maybe feeling trans lag/slow tip in on getting going at lower speeds

rudapa Enthusiast

rudapa

Posted
Posted

Mine is almost unnoticeable unless I watch it on the dash. I'm fine with it so far. I can tell it is there if I try and quickly accelerate while in V4, there is a slightest hesitation. Not a problem though.

gmc1 Enthusiast

gmc1

Posted
Posted

Whats up with the name calling?

 

Cant you see we agree----the AFM feels like a gear shift!

 

Many people want 6 and 8 speed tranny and then complain they can feel AFM.

That is what I dont understand.

 

So stick your name calling up your a@@ hate to see what you would say if i disagreed with you.

No reason we cant keep this friendly.

 

FYI its not the transmission that switches from V4 to V8 ---I think that may have been a typo on your part

so should I call you names now? I dont think that is how this forum goes..

 

One last thing----this is kind of funny----My name is Dick. So you can call me that all day just dont call

me late for supper.

 

 

Haha sorry Richard, I thought you were complaining about me complaining about my truck. I apologize for being a little kid resorting to name calling. And I see now where transmission replaced transition, thank you for bringing that to my attention. One bad thing about reading text, for me at least, (emails, actual text msg's, posts in forums, etc.) is that it's difficult to pick up on tones. I'll try and not jump to conclusions in the future.

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