Disable Cylinder Deactivation

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2018 CX-5 Sport
When I take my foot off the gas and coast, my real time MPG display goes to 99 miles per gallon, but I figured that the engine is idling using very little fuel, not that all the cylinders are not firing. If non were firing it would explain the good down hill engine braking. The transmission would be spinning the inactive engine.
 
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2020 CX-5 AWD
The following is taken from the 2020 CX-5 FSM, in the section 'Fuel Injection Control System':


Deceleration fuel cut zone

  • Purpose

  • Improved fuel economy

  • Control condition

  • If all of the following conditions are met while the vehicle is decelerating

    • Accelerator pedal is fully closed

    • Engine speed is specified value or more

    • Vehicle speed is specified value or more

  • Determination of fuel injection time

  • Fuel injection is stopped.

Mazda is saying that fuel injection is stopped when a set of specific set of conditions is met during deceleration. And it seams reasonable IMO to assume that this shows up on the CD display as all 4 cylinders inactive.
 
I’m surprised more CX-5 owners aren’t complaining about CD. There are quite a few complaints from CX-30 and Mazda3 owners across different forums.

It really ruins it for me. The subtle jolt when switching from 4 to 2 and resonating vibration when running on 2 cylinders under 2k is incredibly annoying for someone like me.
 
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2018 CX-5 Touring
I’m surprised more CX-5 owners aren’t complaining about CD. There are quite a few complaints from CX-30 and Mazda3 owners across different forums.

It really ruins it for me. The subtle jolt when switching from 4 to 2 and resonating vibration when running on 2 cylinders under 2k is incredibly annoying for someone like me.
Wow. Can’t say I ever felt a thing such as a jolt. If mine is switching I don’t know it.
 
Same here...I haven’t been able to tell and I’ve tried. Wish our ‘19 had the display that shows when CD active like the later cars. If nobody told me about the CD, I’d never know our cx5 had it.
 
It’s likely your driving styles or you just don’t notice it because you’re not as in tune with your cars as I am. That’s not at all meant to be offensive I’m really sensitive to things like this.

My wife has no idea it’s happening. Her driving style also includes constantly being on and off the gas, which means CD in’t kicking in as much.

If you’re cruising at around 1500 RPMs with your foot steady on the gas and light load (minor incline) it’s impossible to not notice.
 
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2020 CX-5 AWD
...
If you’re cruising at around 1500 RPMs with your foot steady on the gas and light load(minor incline) it’s impossible to not notice.
Add my 2020 and my daughter's 2019 to the list where this does not ever happen.

If it's 'impossible' to not notice this stuff, then it must be that it's not happening on our vehicles. And please don't suggest that I'm not 'in tune with my car', because I'm a long time DIYer, and am ALWAYS monitoring for anything out of the ordinary with all of our vehicles (which is something that my wife would totally agree with).

Sorry that your CX-5 experience has been ruined, but IMO you're not going to have very much success finding many other owners having the same issue that your vehicle has.
 

sm1ke

Work In Progress..
Moderator
Contributor
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Canada
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'18 CX-9 Signature
It’s likely your driving styles or you just don’t notice it because you’re not as in tune with your cars as I am. That’s not at all meant to be offensive I’m really sensitive to things like this.

My wife has no idea it’s happening. Her driving style also includes constantly being on and off the gas, which means CD in’t kicking in as much.

If you’re cruising at around 1500 RPMs with your foot steady on the gas and light load(minor incline) it’s impossible to not notice.

It's also possible that your car is an anomaly. Have you test-driven other CD-equipped CX-5s to see if they feel the same? I would head to a dealer to test - then you can make a case with the dealer to have the issue investigated if the other vehicles don't exhibit the issue you're describing.

A word of warning though - there is a TSB out there to troubleshoot a similar issue on the CX-30 and Mazda3, but the TSB states that the fix might make the issue worse, and if it does, at that point you'd be SOL.
 

HardRightEdg

US 2020 CX-5 Touring AWD Soul Red
I would hope not considering it was manufactured in July 2020 and I purchased it 2-3 weeks ago.

For me, the vibration that can be felt when running on 2 cylinders isn’t bad at all, it’s the transition from 4 to 2 that bugs me.

I’m sure it isn’t easy to disable, but who knows, maybe it could be as simple as the resistor mod for some Honda’s that only impacts CD( and maybe the temp gauge?).
I can't say I've detected what you've experienced and I think I'm pretty sensitive to what goes on.

As noted previously, I have noticed how this vehicle wants the gas just right to avoid lugging or jolting when shifting from 1st. to 2nd., then less persnickety from 2nd. to 3rd., and not picky after that. I've only once noticed a jerk in a downshift when easing off the gas going uphill into a no-stop 90 degree left turn, kind of an unusual circumstance. Perhaps CD has something to do with it in some circumstances (I've not simultaneously monitored the gauges under these conditions), but my take is that it is inherent in the engine torque/gear ratio/whatnot setup. It took me quite a while to get the hang of it.

When in doubt, more gas! into 2nd. and 3rd. It took me at least 3 weeks to get a better feel for it. The vehicle wants to be driven in a sporty-ish mode. If that doesn't work, I'd have the dealer check it out.
 
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It’s likely your driving styles or you just don’t notice it because you’re not as in tune with your cars as I am. That’s not at all meant to be offensive I’m really sensitive to things like this.

My wife has no idea it’s happening. Her driving style also includes constantly being on and off the gas, which means CD in’t kicking in as much.

If you’re cruising at around 1500 RPMs with your foot steady on the gas and light load (minor incline) it’s impossible to not notice.

lol perhaps, or you could just be imagining things. Sounds more like torque converter lockup to me
 
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2018 CX-5 Sport
I think 2001Snow is feeling something other than the CD transition. The engine has no load on it when it transitions thus no ability to create a jolt, unless like other said, his car has a defect. Maybe one of the rocker arms fell off. A rocker arm getting caught in the cam would cause a jolt.
 
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2020 CX-5 AWD
... Maybe one of the rocker arms fell off. A rocker arm getting caught in the cam would cause a jolt.
Yes, I also had considered the detached rocker arm as a possibility for what the OP of this thread is reporting. However, the big CD thread started by Go Hawks would lead one to believe that a displaced arm would result in limp mode (or worse), anytime the vehicle is pushed hard. But OTOH I guess it can't be ruled out either.

Given that this OP is so upset by what his CX-5 is doing, perhaps he might want to snake an inspection camera in to inspect the arms, as described by Luke_M6 in that same big thread. Or perhaps he's so pi$$ed off by now because no one is taking his side, that we'll never be hearing from him again ;)
 
Calling it a mild jolt is definitely exaggerated but the transition is noticeable to me. And I should clarify, I do not notice every time it switches to 2 cylinders. Mostly under 50 mph with the RPMs close to 2k.

I’m not saying or thinking it’s a problem, just annoying.

It’s not uncommon for people to complain about vibrations in general from CD engines. This includes complaints from Cx-30 and Mazda3 owners with the same engine. Honda owners have also complained about one of the V6s with CD.
 

HardRightEdg

US 2020 CX-5 Touring AWD Soul Red
I detect nothing I would characterize as a vibration in this vehicle under any conditions except one: the steering wheel vibration when the lane keeping assist engages.
 

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