Afm At 80mph

[gmowner4life]

I just came back from a trip to San Antonio. I am definitely going to be calling Black Bear for a tune and get this stupid AFM off!!! The speed limit is 80 MPH from right about Fabens to right about Kerrville on I-10, and when my truck did go in to 4 mode, it went right back in to 8 mode seconds later. Well, each time it went in to 8 mode, it would do a little jerk, which i'm assuming is because of the rate of travel. I don't have any issues with it here in town at 65 MPH, but on the highway it sucked. I now officially hate it!!!

[stadt11]

Internal Server 500 Error

[stadt11]

Def get that removed

[Nick The Great]

I'd just hammer down a bit more, and she'd stay off!

 

Seriously though, it makes sense. If I were doing my Blackbear again, I'd have him turn it off. I don't really have any issues, but I don't have any gains either.

[Wasax3]

I noticed with my AFM the it constantly alternated between V4/V8 when traveling the highway at 75 in cruise as I always do and with the help of my GPS I figured out why!

 

What happens it you get on the highway and set your cruise. The truck uses V8 to get it to that set cruise speed. Once at the cruise speed, It no longer needs as much power, there for it shuts to V4. Seconds after being in V4 the drag against the truck from the wind is so much, that it begins to slow the truck down, and the engine needs more power to maintain the cruise speed, so it switches back to V8.

 

And so it does this over and over again.

 

When ever the truck needs ANY lick of power it kicks back into V8. I wish there was a way to adjust when the truck switched back and forth.

[cmerchant]

Fill your pain:

 

Dear Lance,

 

Thank you for contacting the Chevrolet Customer Assistance Center. We appreciate you taking the time to write us regarding your 2008 Chevrolet Silverado.

 

We apologize, but we are unable to provide the support you requested. All vehicles released from the GM assembly plant are inspected to ensure they comply with government specifications, as well as standards established by the GM Engineering Department.

 

The Active Fuel Management system is an automatic feature on your vehicle and this system cannot be disabled. Chevrolet does not recommend modifying a car or truck after it has left the assembly plant. Changes may adversely affect the vehicle and possibly result in operational problems. Modifying the vehicle could void the manufacturer's warranty on specific items covered under the New Vehicle Limited Warranty.

 

If you should need to contact us in the future, simply reply to this message or call our Chevrolet Customer Assistance Center at 1- 800-222-1020. Customer Relationship Specialists are available Monday through Saturday from 8:00 a.m. to 9:00 p.m., Eastern Time.

 

For more information regarding the maintenance and care of your vehicle, please visit www.GMOwnerCenter.com. This free online service offers vehicle and ownership-related information and tools tailored to your specific Chevrolet.

 

Again, thank you for contacting Chevrolet.

 

Sincerely,

 

The Chevrolet Consumer Support Team

[stadt11]

this system cannot be disabled

 

HAHA, little do they know!

[rvsahs]

I'd just hammer down a bit more, and she'd stay off!

 

Seriously though, it makes sense. If I were doing my Blackbear again, I'd have him turn it off. I don't really have any issues, but I don't have any gains either.

 

Good answer!

[alaska511]

Mine won't come on after about 72...maybe with a tail wind.

[uh6tdrvr]

Pretty much useless unless you are going downhill!!!

[cerbomark]

mines off too,, and yes it can be adjusted how long and when it kicks in and out, not worth the effort imo... no noticeable difference in mileage with the tune minus the afm

[pm26]

My truck actually has a phantom switch to turn off the AFM I do not have!!!!!!!!

 

Seriously though, I get about 19 MPG when cruising around 75 MPH on a level highway. Without any annoying jerks and clunks.

[pm26]

I just came back from a trip to San Antonio. I am definitely going to be calling Black Bear for a tune and get this stupid AFM off!!! The speed limit is 80 MPH from right about Fabens to right about Kerrville on I-10, and when my truck did go in to 4 mode, it went right back in to 8 mode seconds later. Well, each time it went in to 8 mode, it would do a little jerk, which i'm assuming is because of the rate of travel. I don't have any issues with it here in town at 65 MPH, but on the highway it sucked. I now officially hate it!!!

 

This cracks me up. I have been criticized by some on this forum for my dislike for the AFM - but I suspect that I have been right all along. It's nothing but a useless gimmick to help GM show higher MPG numbers on paper. If they provided an ON/OFF switch like most vehicles have for the traction control, then the system could be useful under some conditions.

[MS3DALE]

I don't have any issues with the AFM in my truck,I actually think its helps me....*A LITTLE*

But something tells me that in the next few years all this AFM and DOD stuff will be gone!!

[Z'06]

I have been criticized by some on this forum for my dislike for the AFM - but I suspect that I have been right all along. It's nothing but a useless gimmick to help GM show higher MPG numbers on paper. If they provided an ON/OFF switch like most vehicles have for the traction control, then the system could be useful under some conditions.

 

Well, there are a lot of people on this forum who are afraid of messing up their warranty and who figure that if it was engineered that way, it's somehow better by design (when we all know or should know that building automobiles is a collaborative effort among engineers, accountants, marketing, and investor relations professionals, each with a hand in the design).

 

It stems from a fundamental lack of knowledge as to which mods can actually only *help* the engines last longer, and understanding the ramifications of the Magnuson-Moss Act. Uninformed dealer service reps only exacerbate this issue.