Range D.F.M. disabler

Jac365 · May 5, 2020

I received an Email from Range Technology today stating that the disabler for D.F.M. vehicles is now available. I am aware that several members of this site were beta testers. Can any of the folks who were testing them give any feedback on how well the units perform? Any issues that arose? Did the test units have to be sent back for updates? Overall satisfaction?

Bob Ross · May 5, 2020

I beta tested and I love it. I will continue to use it. I recommend the buy if you want to have it in V8 and stop auto/stop start. I only take mine out when going to the dealer for service and then plug it right back in.

I had no real issues to speak of though you will feel a more rough transmission shift. At least i did with my 8 sp trans. No CEL or any other issues. I never had to send my unit back for any updates. Worked from day 1 of beta testing the whole way through. I did notice a slight drop in MPG by about 2 mpg but that is because I was having fun in V8. When on the highway I was only about .2-.5 mpg less on normal highway trips. So really not that bad.

JohnTz · May 5, 2020

Can you please tell me why you would use this in the first place? I understand turning off the auto start stop but why disable the DFM and cause rough shifting and higher gas use? DFM is seemless. Do you actually feel it in some way? Trying to figure it out if I am missing something?

Bob Ross · May 5, 2020

1 hour ago, JohnTz said:

Can you please tell me why you would use this in the first place? I understand turning off the auto start stop but why disable the DFM and cause rough shifting and higher gas use? DFM is seemless. Do you actually feel it in some way? Trying to figure it out if I am missing something?

There are plenty of threads on this but for me I paid for a V8 and I want a V8. Besides the fact that AFM was plagued with lifter failures and oil consumption issues. The people who had their engine in V8 all the time has much less of this happen. For me the little bit of fuel savings won’t even out $$$ wise for repair costs. Granted it’s under warranty for repairs. But like I said before I paid for a V8 and want a V8 not some other number of cylinders.

Jay P · May 5, 2020

While they released a DFM disable, it doesn't work on anything with the 10 speed trans yet.

Jay

JohnTz · May 5, 2020

32 minutes ago, Bob Ross said:

There are plenty of threads on this but for me I paid for a V8 and I want a V8. Besides the fact that AFM was plagued with lifter failures and oil consumption issues. The people who had their engine in V8 all the time has much less of this happen. For me the little bit of fuel savings won’t even out $$$ wise for repair costs. Granted it’s under warranty for repairs. But like I said before I paid for a V8 and want a V8 not some other number of cylinders.

Ok thanks for the explanation. I guess I knew that it had DFM when I purchased it so I knew it was a V8 that has advanced cylinder fuel management so it doesn’t bother me and it equals better fuel mileage and it’s warranted.

I think to try and put some aftermarket device on my 6.2 that has such complex control logic and turn off something that was designed in deeply into the way the whole systems is intended to function may result in bigger problems.

I appreciate the explanation. It’s not for me.

thanks again.

Jac365 · May 6, 2020

I had one in my old 2012 5.3 Sierra SLT Z71. Only "issue" I ran into with it was run the vehicle without it for a day or two PRIOR to having an emission test if your state requires one. My fist time I removed it when I got to the test station, which did not allow the computer to "set" to its required test parameters. Left it out for a couple days and returned to the test station without issue.

I still have the old Range box. I wonder if it could be updated to work on my 2019 DFM truck?

Stephen L. Pannell · August 10, 2020

On 5/5/2020 at 4:54 PM, Jay P said:

While they released a DFM disable, it doesn't work on anything with the 10 speed trans yet.

Jay

I inquired about this issue to the Range tech dept. Here is their answer: We unfortunately do not officially support the 10 speed vehicles yet. The units that we currently have will generally work for the 10 speed vehicles, but there are some minor kinks that still need to be worked out with them before we officially release anything.
this tells me that it may or may not work with the 2019 10 speed new body style

Stephen L. Pannell · August 11, 2020

So I went ahead and picked up one from Summit Racing near me and plugged it in. Started and drove about 30 miles and so far it's working like it should. V8 sound all the time. With the Borla catback exhaust it now sounds like a truck all the time. No engine stop at redlights. So far so good. Will drive it some more and report back in a few days. I did keep the box and receipts just in case.

Stephen L. Pannell · August 24, 2020

well, almost 2 weeks have gone by and I have driven right at 500 miles and many start stops along the way. So far the AFM/DFM unit has worked to perfection. NO codes have been thrown and the automatic start stop is no longer a PITA. As for fuel mileage I can't tell since most of the driving has been in town. I still average around 15 mpg in town driving. 2019 High Country 6.2l 4x4 crew

econometrics · August 24, 2020

5 hours ago, Stephen L. Pannell said:

well, almost 2 weeks have gone by and I have driven right at 500 miles and many start stops along the way. So far the AFM/DFM unit has worked to perfection. NO codes have been thrown and the automatic start stop is no longer a PITA. As for fuel mileage I can't tell since most of the driving has been in town. I still average around 15 mpg in town driving. 2019 High Country 6.2l 4x4 crew

Thanks for the real-world feedback. I usually get 15-16mpg in town with my 5.3L RST, so it seems like the lack of DFM hasn't really hurt you too much so far. I'm sure it really only puts a dent in MPG on longer, flat highway runs.

Tigerwitha88 · August 25, 2020

On 5/5/2020 at 6:15 PM, JohnTz said:

Ok thanks for the explanation. I guess I knew that it had DFM when I purchased it so I knew it was a V8 that has advanced cylinder fuel management so it doesn’t bother me and it equals better fuel mileage and it’s warranted.

I think to try and put some aftermarket device on my 6.2 that has such complex control logic and turn off something that was designed in deeply into the way the whole systems is intended to function may result in bigger problems.

I appreciate the explanation. It’s not for me.

thanks again.

Nearly everyone that runs one does so to avoid oil consumption issues that will lead to piston replacement and/or lifter failure in the future. Jury still out on the 19-20 models I would say but anyone that went through it with the 2007+ models runs AFM/DFM delete.

EricTheRed · August 26, 2020

Someone correct me if I’m wrong, but can anyone with the 10speed/6.2L get the same result by pressing the auto start/stop button and driving in L9... the only difference being losing 10th gear?

diyer2 · August 26, 2020

My guess is yes.This would stop start/stop and stop v4.

Jay P · August 26, 2020

1 hour ago, EricTheRed said:

Someone correct me if I’m wrong, but can anyone with the 10speed/6.2L get the same result by pressing the auto start/stop button and driving in L9... the only difference being losing 10th gear?

Yes.