2014+ AFM (Active Fuel Management)

Mtxkidd · November 12, 2016

I put a brand new range device with the latest update on my 16 Sierra Denali 5.3 with 8 speed transmission it worked for a day then got CEL and driving crappy called range directly and they told me that it dosent support the 8 speed tranny yet and to try back in a month or so to see if they have solved the problem. My question is has anybody tried the Diablo sport sprint AFM deactivation device that's the same exact thing as range only turns off AFM I was told there's works with the 8 speed

TedH · November 22, 2016

AFM with my Flowmaster Force II system is so annoying that I am going to re-install my stock exhaust (with the flap) but with a Borla muffler. I have resorted to using M5 setting on transmission when driving around town (mostly city traffic) as the AFM switching happens too often and is very noticeable. The 4Cyl mode really has a DRONE that bugs me. Added an exhaust system to improve the sound/performance and not sure it was worth it with AFM.

JacobC1983 · December 15, 2016

The Range Device has really calmed down my 6 speed transmission. I don't get nearly the surges and changes in pressure from the vehicle going in and out of V4 mode anymore. The lack of confusion has caused the transmission to shift less harshly because it always wanted to shift when it kicked back into V8 mode.

One of the wierdest things for me was when I would be driving along, AFM would kick into V4 mode, and the RPM would raise to keep the same power, but I guess this would increase fuel economy. Now the truck is in transition less, which results in a better driving experience.

The Range was worth every penny so far.

ShamrockShooter · January 25, 2017

What is the latest version of the Range firmware?

F4Gary · January 26, 2017

I installed a Range device on my new to me 2014 5.3L and other than looking on the dash to see it never goes in V4 mode I can't tell any difference.

I've had no problems with CEL lights or transmission shifting.

I did lose about 3 mpg around town, and I ran the battery down once after not using the truck for about 3 days(live and learn Doh!)

I think I'm going to alternate 1 tank of gas with it, and then 2 tanks of gas without the Range.

I'm a car guy, and I couldn't tell when my truck went into V4 without looking at the dash.

Not sure how you can tell if your transmission fluid pressure is surging as there is no readout.

mookdoc6 · January 26, 2017

When cruising at 65-75 somewhere in there you can feel at times a surging as it goes from V4-V8 and back and forth.....Most of the time they are almost imperceptible other times it will ever so slightly surge......it's present, it's there it's not that big of deal to me I can cruise all the way to work in V4 and get 22+ all day long at 75.......

ShamrockShooter · February 3, 2017

I just got my range. used it today for a 60 mile trip for work, mostly highway, speeds between 55 and 70, temp about 25 degrees. on the way there with range it was 21.1 mpg. on the way back (into the wind and uphill) i averaged 20.0 mpg. I could immediately notice how much smoother the truck drove and shifted.

my only complaint, is the second i plug in the range, every bump it hit, it makes a plastic loose rattle sound. i shook the range unit, and it doesnt make any noise, but the second i plug it back in, the rattle comes back on every bump i hit. i could be the port it plugs into. not sure. anyone else notice a rattle after hitting bumps with the range plugged in?

GMC2015 · February 3, 2017

I'm just gonna add this: If anyone that drives a 4.3 with AFM and has the dreaded vibration/shake in V4 mode, either clamp or delete the exhaust valve. Doing this made the truck SO much smoother with the v4-v6-v4 transitions, and the shake is 95% gone. I haven't even noticed any drone with the valve open.

Joe_Lee · February 6, 2017

I purchased the Range AFM disable device last week from an online site. I drove it a day or two and it did great for a little while then check engine light and limp mode.

I called and spoke to Katie at Range and she told me they just updated a new version for 2017 models. So I sent the other module back and ordered the newest software version, it should be here in a few days.

I previously ran two Range devices on a 13 Silverado and a 14 Tahoe and both worked great.

Edited February 6, 2017 by Joe_Lee

BigBlueLB756 · February 6, 2017

What version do you have?

ShamrockShooter · February 8, 2017

I just got one from range last week. It was version 7.8rx with a date of 12/29/2016

Joe_Lee · February 8, 2017

Update on mine. The newest version (8.1) came in the mail Monday. I've driven about 100-150 miles with it plugged in and so far no issues. I will say that the 7.8 version didn't cause a light for the 1st 100 miles or so either.

I'll be putting about 100 miles on it today so I should know if the 8.1 causes any glitches or not.

ShamrockShooter · February 15, 2017

I was getting 18.5 MPG in normal commute b4 range. First 2 tanks with range were 16.5 MPG. Same driving style and distance. I'm not sure I want to give up 2 MPG for smoother shifts and better driveability.

aaronarf · February 16, 2017

Anyone on the fence about disabling AFM...go ahead and just do it. Unbelievable how much more enjoyable driving the truck is. I do a lot of two lane country highways where I'd go from 4cyl to 8cyl often, didn't realize how much power terrain vibrations AFM caused.

Ordered from Range last weekend and received 8.1 version which so far is working great on my 5.3, 8 speed.

Dnt · February 16, 2017

Guys I have a 6.2 8spd and I am using the Hypertech hand held to set the AFM to only come on at highway speeds. I had the GM Borla catback nstalled and the V4 noise at slow speeds was annoying. As far as gas mileage I cannot tell that the AFM coming on at highway speeds only makes any difference.