Range AFM Unit

[Daniel Goss]

New owner and member here. For decades my "fun" cars have been Corvettes. But at 77 yrs old and bad knees, it has become too much of a chore to simply get in and out of my current 2019 Z06, so yesterday I made a trade deal and today I will be taking home a new 2025 CT5 Blackwing. In my Corvette I have been leaving a Range device plugged in, as I just don't like cylinder deactivation, or AFM. Does the Blackwing also have some type of cylinder deactivation, and if so, are any of you preventing the engine from going into 4 cylinder mode? Range Technology does not make a plug in unit for the Blackwing, and I am not interested in doing an aftermarket tune, so what options are any of you using?

 

[Sully]

The LT4 in the BW does not have AFM/DFM. No Range needed (I have one in my L87 6.2).

 

[Daniel Goss]

I appreciate the quick response. That is good news. I should have mentioned that my BW is an auto transmission, so it really has no AFM type system? That surprises me, but I like the idea.

 

[jwolf99]

My 2022 5BW with auto has AFM. It only comes on when in Tour mode and generally only while coasting with little to no throttle. I believe the 2023-2026 5BW autos continue to have AFM as well. See my original post on this

AFM? (thread here)

Since I rarely drive in Tour mode, it's hardly ever on for me.

 

[Sully]

My 2022 5BW with auto has AFM. It only comes on when in Tour mode and generally only while coasting with little to no throttle. I believe the 2023-2026 5BW autos continue to have AFM as well. See my original post on this

AFM? (thread here)

Since I rarely drive in Tour mode, it's hardly ever on for me.

Interesting, i stand corrected. I have a MT so perhaps AFM was included in the auto but AFM wasn't included in the manuals?

Then again, there isn't a V8/V4 visual indicator (in the MT) that I'm aware of nor an audible change like I noticed with my 21' Suburban 6.2.

 

[jwolf99]

Interesting, i stand corrected. I have a MT so perhaps AFM was included in the auto but AFM wasn't included in the manuals?

Then again, there isn't a V8/V4 visual indicator (in the MT) that I'm aware of nor an audible change like I noticed with my 21' Suburban 6.2.

Correct. No AFM in cars with MT nor is there a V8 dash indicator of any sort like you see in photo of my original post.

 

[Finally-a-V]

With the 5BW, AFM (cylinder deactivation) is on the automatics only. There is a dash light in green that will show V4 when the cylinders are deactivated. Usually, the only time I see it is when using cruise control. Any slightly spirited driving will eliminate the use of AFM.

 

[668LT4]

I know I have read manuals have the hardware in the engines, but it does not function. Not sure if that is accurate or not.

 

[jwolf99]

I know I have read manuals have the hardware in the engines, but it does not function. Not sure if that is accurate or not.

Yes, it's accurate. The ECM controls when a circuit board shuts down 4 cylinders via solenoid during low load conditions. All of the LT4s are supposedly the same but the ECM in the MT never triggers the shutdown.

A couple of informative videos on how the system works.