2025 Tahoe LS cylinder deactivation indicator

[aJohnM1948]

My 2018 Tahoe LS had a V8/V4 indicator on certain pages of the DIC. I can’t find an indicator like this on my 2025. Is Chevy trying to pretend cylinder deactivation doesn’t exist because of the problems it can cause? I read previously it caused problems in 2% of prior generation vehicles and never read a root cause. Was it variation in machining tolerances (my bet), dirty oil, driving habits, something other? I could always connect my Autel OBD2 meter on to monitor cylinder deactivation if I wanted to ensure an after market product like a Range DOD/DFM device is doing it’s job of keeping the car in V8 mode, but that’s a PIA if one would have to do that periodically to insure such devices were (still) doing their job.

 

[Big Mama]

Not sure about yours but my ‘23 Sierra has DFM same as AFM but can turn off more then or less than 4 cylinders. On my older truck I could set the DIC to display V8 or 4 when it switched but I haven’t found it on my newer one.

One of the major problems of AFM was the lifter failing. Some may have been from bad oil or driving hard but the majority weren’t.

 

[PPK_]

My 2018 Tahoe LS had a V8/V4 indicator on certain pages of the DIC. I can’t find an indicator like this on my 2025. Is Chevy trying to pretend cylinder deactivation doesn’t exist because of the problems it can cause? I read previously it caused problems in 2% of prior generation vehicles and never read a root cause. Was it variation in machining tolerances (my bet), dirty oil, driving habits, something other? I could always connect my Autel OBD2 meter on to monitor cylinder deactivation if I wanted to ensure an after market product like a Range DOD/DFM device is doing it’s job of keeping the car in V8 mode, but that’s a PIA if one would have to do that periodically to insure such devices were (still) doing their job.

I will say… the 5.3 has been around a while.. my guess is that clean-up of the blocks is now poor.. and the tooling to do the block/heads has seen better days. First figure is the 5.3 filter and what magnetic contents there are.. figure two is the first drain of my ‘24 yukon.. right block is the first drain of a ‘25 slt with a 3.0. I think the newer engine and new tooling shows a lot less issues than our older V8s.

If you really look at the middle drain oil.. there is a lot of aluminum and some iron too in the oil. Not good

I think… you do a drain at 25 hrs. I did another drain at 50 hrs it was a lot cleaner.. you have to have clean oil for an engine to last.. i think carbyte is the afm eliminator or just run in 9 gear.

And finally if had to do the yukon purchase again with 5.3 in it.. would do a 3.0.. bummer…

Good luck!

 

[Vladimir2306]

On the T1 generation there is no V4/V8 image, but the system itself works.

 

[Marky Dissod]

You likely do not have only V4 mode - that'd be AFM (Engine Half@$$).
Your 2025 more likely has V7 mode, V6 mode, V5 mode, V4 mode, V3 mode, V2 mode, I2 mode, and possibly 0-cylinder mode.
GM probably wanted to NOT call your attention to the Cylinder Confusion.
If you roll down the window, your ear will eventually learn to discern at least some of those modes.

 

[Big Mama]

Very true ^^^

 

[iamlegion]

My 2018 Tahoe LS had a V8/V4 indicator on certain pages of the DIC. I can’t find an indicator like this on my 2025. Is Chevy trying to pretend cylinder deactivation doesn’t exist because of the problems it can cause? I read previously it caused problems in 2% of prior generation vehicles and never read a root cause. Was it variation in machining tolerances (my bet), dirty oil, driving habits, something other? I could always connect my Autel OBD2 meter on to monitor cylinder deactivation if I wanted to ensure an after market product like a Range DOD/DFM device is doing it’s job of keeping the car in V8 mode, but that’s a PIA if one would have to do that periodically to insure such devices were (still) doing their job.

I guess what is it you’re trying to accomplish by seeing this information? When I’m driving my $85k truck I’m not worried about which specific cylinder is firing, or in what order.

I think people are spending so much time on the internet in AFM/DFM research holes that somehow being able to monitor it will somehow give some peace of mind.

 

[Marky Dissod]

Strongly suspect that the only way to know if the engine is 'lapsing' into V7, V6, V5, V4, V3, V2, or 0-cylinder mode,
would be a mechanic's live diagnostic scanner.

 

[Big Mama]

The truck I had with AFM made it easy to see V4 but I couldn’t really feel any changes under normal driving. My newer truck with DFM and 10 speed transmission makes it even more seamless. I guess a really good tuner could create a display for you like HP tuners display.