Can see how that would be annoying. When in 4th at 30 to 40 mph on smaller roads, mine would swap to 4 cylinders so I tend to swap into touring mode most of the time which on my car deactivates the cylinder shut down. It didn't feel right to me it cutting in out out all the time. I can see how on an auto or US spec car that would be really annoying. As you say 1 mpg is not really worth worrying about. I'll have a play next time I'm on a motorway and see what difference it makes.
C7 cylinder deactivation
- Thread starter RussTeens
- Start date
Roscobbc
Moderator
If it ain't broke (or at least 'partly' broke) as a 're-programmer 'don't fix it and potentially land yourself other unreleated issues?
teamzr1
Supporting vendor
Since I started keeping records via my custom tuning process, saved just about 10,000 OBD2 scanner recordings I analyzed
Not one going back to late 1990s GM vehicles, most of them F & Y body has had engine problems when I turned off DoD/AFM
Very simply, the PCM (engine controller) believes the engine does not have DOD so is not commanding any of its functions
thus the engine valve train functions as they always have pre DOD/AFM
Not one going back to late 1990s GM vehicles, most of them F & Y body has had engine problems when I turned off DoD/AFM
Very simply, the PCM (engine controller) believes the engine does not have DOD so is not commanding any of its functions
thus the engine valve train functions as they always have pre DOD/AFM
UKBeancounter
Committee Member
Ian Allen are official GM / Chevrolet Europe sellers. Given that any ECU alteration usually invalidates the warranty I am not surprised they don't want to touch things.
Not read anything about engine failures after AFM delete, only the GM service/recall notices on what dealers should do when lifters seize in the head due to AFM malfunctioning. If its going to blow up, its going to blow up !
Not read anything about engine failures after AFM delete, only the GM service/recall notices on what dealers should do when lifters seize in the head due to AFM malfunctioning. If its going to blow up, its going to blow up !
teamzr1
Supporting vendor
GM even does not want 4/8 cyl crap
Notice on Z06 and ZR1 engines do not have DOD/AFM as already have to pay a gas guzzler tax
so it is clear it is all about games as to federal MPG mandates and politics
If you drove through areas where the elevation changes up/down are or at higher elevations where engine performance output is less
would you want to do that with one 1 or 2 legs
Same thing with DoD/AFM changing loads onto auto tranny
where Hp/Tq is half, but the mass going up hill is worse as load
Notice on Z06 and ZR1 engines do not have DOD/AFM as already have to pay a gas guzzler tax
so it is clear it is all about games as to federal MPG mandates and politics
If you drove through areas where the elevation changes up/down are or at higher elevations where engine performance output is less
would you want to do that with one 1 or 2 legs
Same thing with DoD/AFM changing loads onto auto tranny
where Hp/Tq is half, but the mass going up hill is worse as load
Digger John
CCCUK Member
In my euro spec C7 Grand Sport the AFM only operates in Ecco mode so i run in touring mode all the time for general driving so never switches to V4 mode.
This is exactly what I do in my '18 Grand Sport
Rob59C1
Administrator
I can see this issue has been well covered but I'd just like to be sure about something. I have a 2014 Z51 manual euro spec which as has already been said, only allows cylinder deactivation in Eco mode, so is easily avoided. However, I'm now considering a US spec Auto. So my question - is cylinder deactivation always on in every mode for 2019 Stingrays, Z51s, & Grand sports unless modified?
Chevrolet
CCCUK Member
Not sure why you asked the question Rob? Per "Stingray" above, US cars can go into AFM 4 cylinder running in all drive modes, including "Track". I'm not aware that was changed on 2019 or later cars? So options to get rid off that look like the Range Technologies plug in device, or a remap like the one Keith did for UKBeancounter above?
Rob59C1
Administrator
Just checking that it applied to 2019 models as the experience of the contributors to this thread don't or didn't have 2019 C7s that's all. If I'm going to splash out on a 2919 I need to understand & be sure of all the implications. Due diligence & all that! BTW does it really apply to Grand Sports with auto transmission too, as per my question?
Chevrolet
CCCUK Member
Yes, UKBeancounter's car above is a US spec Grand Sport.
Rob59C1
Administrator
Thanks, although his is 2017 so still not totally sure it applies to 2019. which is why I asked for confirmation. Just hoping GM came to their senses. Especially with a GS & a Z51, which are aimed at track use. I guess their rational was, on the track use the paddles, hence no deactivation with manual selected?