2019 Sierra DFM - RANGE WORKS!

anthony2558 · April 19, 2020

On 2/5/2020 at 2:53 PM, ls1wolf said:

First off, I don't post much here - mostly on CorvetteFor**….. But wanted to share something that RANGE hasn't told us about for the 2019-2020 trucks with DFM.

I had a 2016 Sierra 5.3 AFM that I bought a range device to keep it in 8 cylinder mode because of the MBRP exhaust. Yes. MBRP... I loved it. Sounded great and was very easy to install - and CHEAP! The range device worked great. I would average 20.5-21mpg over the summertime and 18.5-19mpg in the winter (lovely Michigan winters). Had the truck for over 50,000 miles before I traded it in for my 2019.

Fast forward to my new 2019 Sierra 5.3 DFM. I purchased a new MBRP, as I gave my old exhaust to my dad for his truck (and yes my 2016 exhaust fit on a 2000 Sierra!). I was told that the Range from my 2016 would not work on my 2019 truck, so I didn't install it at first. But, read that RANGE did have a device for the start/stop feature. So I figured I would give it a try.... and it worked... No start/ stop and only 8 cylinder mode.

I know have 8,****** miles on my 2019 truck. Have towed with it, daily drove it, everything... Range works. But...

I notice that when the truck is cold, or the trans temp isn't over 100 *f, the DFM is still active. Once over 100*F, the truck stays in 8 cyl mode all the time - never switching to 4cyl or even the lovely 2 cyl mode. Again, but...

I was noticing my fuel economy wasn't great. Only 17.5 (here in winter of Michigan). I did average 20.5mpg on a 500 mile round trip in October (50-60* temps) But it still wasn't as good as my 2016 mpg's.

So the last week I have pulled the range out - and now I hear the lovely 4 and 2 cyl mode. Especially noticeable with the MBRP exhaust. At 50mph it isn't bad helicopter noise but its still there. At 75mph, the truck will not go into DFM, at least with cruise control active, for what ever reason. My MPG's are back, and back by a lot. I'm now seeing 19-19.5mpg (still winter) compared to the 17-17.5mpg with the range 8cylinder mode.

So moral of the story - a range device from a 2016 truck works on a 2019 with DFM. Again, not initially at cold, but will after a short 5 min drive.

Also a video of my 2019 with the MBRP is on youtube - have no idea how to post it here. But look up LS1wolf 2019 Sierra MBRP.

-Mark

OP do you still have the range installed?

Edited April 19, 2020 by anthony2558
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TRKLGND · April 21, 2020

I just push the button to turn off Stop/Start. A completely free mod that works EVERY time!

As for DFM, can't say that I have ever heard it switch modes. In fact, the only time I ever heard AFM was in my 2012. The list of my current and previous trucks is in my signature.

Never modified exhaust on any of them either. I tow a boat and every modified exhaust I have ever heard suffers from drone (some more than others) when under load. Not what I want to listen to for hundreds of miles. Just my opinion.