Cylinder Deactivation Update

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2018 CX-5 Sport
When I bought mine in late 2018 I knew it had CD, but I was assured by a couple of mechanics about Mazda's brilliant engineers and not worry about it. Then of course the rockers falling off issue materialized. I rather it not have CD, the fewer complexities to go wrong the better.
 
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2019 Cx-5 sport
Just to chime in , I didn't know about cd with this cx5 when I bought it and
no one at the dealership said anything about it. None of the reviews I read
mentioned it either, and it wasn't printed on the invoice.
Found out about it on this site first time.... wouldn't have bought
this vehicle if I'd known.... , still, cx5 is doing ok right now..
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
Just to chime in , I didn't know about cd with this cx5 when I bought it and
no one at the dealership said anything about it. None of the reviews I read
mentioned it either, and it wasn't printed on the invoice.
Found out about it on this site first time.... wouldn't have bought
this vehicle if I'd known.... , still, cx5 is doing ok right now..
You’re not alone. The salesmen at my Mazda dealer knew nothing about the new cylinder deactivation “feature” in 2018 when I was checking out the CX-5. See, if CD is such a great thing, how come Mazda North Amerucan Operations don’t educate the salesmen at Mazda dealerships and make them using the CD as a great selling point? Instead Mazda seems to be afraid of mentioning the CD may be because it has bad reputation from history?
 
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2019 CX-5 Signature
Just to chime in , I didn't know about cd with this cx5 when I bought it and
no one at the dealership said anything about it. None of the reviews I read
mentioned it either, and it wasn't printed on the invoice.
Found out about it on this site first time.... wouldn't have bought
this vehicle if I'd known.... , still, cx5 is doing ok right now..

If it was a concern, you would have known of it before buying. It's nothing like the gas in oil issue the CR-V's experienced. That was headline news. Don't let a few people on the forum make you question your decision. Just enjoy it...
 
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CX5 GT
also if memory serves me right, the issue with cd software was related to mitsubishi ecu software from the factory. Most cx5 I have checked, mine as well, are Denso Ecu. they did update the software anyway with the latest at that time. v.J
And newest cx5s come with even newer ones.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
also if memory serves me right, the issue with cd software was related to mitsubishi ecu software from the factory. Most cx5 I have checked, mine as well, are Denso Ecu. they did update the software anyway with the latest at that time. v.J
And newest cx5s come with even newer ones.
This story of wrong version software used with different vender, the Mitsubishi PCM instead of Denso, was mentioned by Go Hawks which was given by Mazda North American Opetations. But if you read the official chronologies submitted to NHTSA by MNAO about cylinder deactivation recall in post #93 by zroger73, no such thing is mentioned. MNAO received the first field report of rocket arm fallen off on 1/31/2018, and determined an inappropriate specification of oil pressure control signal response as the root cause on 11/2/2018. Then Mazda found another root cause which is the software programming bugs during transitions between cylinder deactivation modes on 1/24/2019, and initiated a PCM software design change on 3/29/2019.

I enjoy reading the chronologies associated with recalls. This information can be found under "Associated Documents" for a recall on the NHTSA website.

Here's the chronology for one of the recalls on the 2018-2019 CX-5:

View attachment 227863
 

HardRightEdg

US 2020 CX-5 Touring AWD Soul Red
If it was a concern, you would have known of it before buying. It's nothing like the gas in oil issue the CR-V's experienced. That was headline news. Don't let a few people on the forum make you question your decision. Just enjoy it...
That's a good way to look at it.

I have the same view toward the direct injection carbon build-up issue which may never materialize into something that needs attention. I've had mpg drops after a fuel injector cleanings on two different low mileage vehicles and never had it done since with vehicles humming along up to 150,000 miles. The lesson is if it ain't broke don't fix it, don't worry, be happy if you were happy with the purchase in the first place.

My thinking is take a benchmark on your mpgs in your typical driving, in my case 32-33 in long haul highway driving at 72 mph, give or take, and 28-29 in mixed rural/suburban/highway with some short hops mixed in. If the engine fells good, sounds good, and the mileage stays relatively steady, then just enjoy the ride and don't f*ck with mother nature, so to speak. Just don't skimp on oil changes.

There's not much point in obsessing about what might or might not happen. And as you indicate, it's not like the competition doesn't have their own isolated issues. Consumer Reports continues to give used first generation CX-5s through and into the 2018+ high reliability marks based on subscriber trouble reports which illustrates how a cluster of complaints is not reflective of the overall odds.

There is one concession I'm making with this direct injection engine: I'll be steering clear (pun intended) of no name gasoline off the Indian reservation even though my other vehicles have run great on it. Sunoco is Top Tier and it's nearby. [Edit: I see now that Sunoco is no longer listed on the Top Tier web site. Evidently they suspended their participation in May 2020 due to Covid.] That ought to do it. Too bad, though. The reservation undercuts everybody by 20-30 cents because they don't charge the state fuel tax even though the tax break is supposed to go only to the tribe members. So I guess I'll be complicit in violating the law only half the time. Or is it a law if it is not enforced, like a speed limit signs? ;)
 
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Fredericton Canada
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2018 CX-5 GT
When I got the CD recall notification for the software upgrade I had already heard about the rocker issues. I questioned my service rep about this when I took my vehicle in for the recall but he assured me that the software update would resolve any of these issues so that put my mind at rest.
 
Think we can move on about CD as an anxiety trigger. Since the recall, reports of engine trouble have not been materializing. This engine is used in CX-30’s, Mazda 3’s, Mazda 6’s and increased failure rate just isn’t being reported.
 
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2018 AWD GT Premium Red/Black
This story of wrong version software used with different vender, the Mitsubishi PCM instead of Denso, was mentioned by Go Hawks which was given by Mazda North American Opetations. But if you read the official chronologies submitted to NHTSA by MNAO about cylinder deactivation recall in post #93 by zroger73, no such thing is mentioned. MNAO received the first field report of rocket arm fallen off on 1/31/2018, and determined an inappropriate specification of oil pressure control signal response as the root cause on 11/2/2018. Then Mazda found another root cause which is the software programming bugs during transitions between cylinder deactivation modes on 1/24/2019, and initiated a PCM software design change on 3/29/2019.
yrwei52,

This sounds typical of firmware development and debug for a complex electro-mechanical system. Occurrence rate was low, probably never encountered in lab testing. It may have been difficult, or impossible to reproduce in controlled, instrumented conditions. They may not be able to pinpoint for certain which bugs or marginal algorithm may have actually resulted in the field failures when there were so few. But the code got a bunch of scrutiny and it looks like a couple steps of refinement in response.

I'm not losing any sleep over it.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
yrwei52,

This sounds typical of firmware development and debug for a complex electro-mechanical system. Occurrence rate was low, probably never encountered in lab testing. It may have been difficult, or impossible to reproduce in controlled, instrumented conditions. They may not be able to pinpoint for certain which bugs or marginal algorithm may have actually resulted in the field failures when there were so few. But the code got a bunch of scrutiny and it looks like a couple steps of refinement in response.

I'm not losing any sleep over it.
My response is to the story of wrong version of the firmware in Mitsubishi PCM which caused fallen rocker arm, but the Denso PCM is fine. Based on Mazda’s official chronologies that story is not true.

I understand there’s no software or firmware which is 100% bug-free. But this isn’t my concern on cylinder deactivation.

Since I keep my vehicle forever, I’m worried about the long-term mechanical problems on cylinder deactivation which have been consistently proven by those engines implemented CD since 1980’s.
 
Guys, here's the question people want to know.

If you have the 2.5L engine with CD and had the software fix, how many miles have you travelled and is the engine still holding up? Do you experience harsh vibration during the transition?
 
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GA prior 16 CX5 GT
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20 CX5 GT + Prem
I have an early 2020 GT with no issues and can not tell when CD kicks in or out. Even looking at the monitor it is hard to hear/feel a change. Due to Covid only 5500 miles mostly 10 mile trips to town.
 
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CX5 GT
Guys, here's the question people want to know.

If you have the 2.5L engine with CD and had the software fix, how many miles have you travelled and is the engine still holding up? Do you experience harsh vibration during the transition?

aprox. 9000 miles here, after the software fix. Did it July 2019.
I have never had any vibrations that you mention, even before.
 
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2018 CX5 GT, Metallic Machine Gray and 2018 MX-5 RF GT, Soul Red
As noted in the other thread recall done in July 2019 & travelled about 16,000 km since the recall. No vibration. Can not tell when CD goes on or off.

Wade
 
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2018 CX-5 Sport
I too haven't been driving much but I have never been able to detect transitioning from 4 to 2 or 2 to 4. It will take many years before knowing if there are ill effects if any.
 
Thanks for your feedback. I would say let's put this CD behind us and let's just enjoy the car the way it meant to was intended.

I just picked up a 2020 with Polymetal Grey colour today. One weird thing I noticed was that under moderate breaking from high speed (let's say 70mph to 10mph) I noticed the rear breaks are making this "mild rumbling noise". Sounded like touk, touk, touk...as in, the ABS system is constantly kicking in even under mild breaking.

I found a section in the manual which reads "this vehicle has a power-assisted brakes that assist automatically though normal use" - could that be it?

Any ideas idea? Car is only has 60 miles on it, so maybe it needs time to break in?
 
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Antoine

Administrator
Thanks for your feedback. I would say let's put this CD behind us and let's just enjoy the car the way it meant to was intended.

I just picked up a 2020 with Polymetal Grey colour today. One weird thing I noticed was that under moderate breaking from high speed (let's say 70mph to 10mph) I noticed the rear breaks are making this "mild rumbling noise". Sounded like touk, touk, touk...as in, the ABS system is constantly kicking in even under mild breaking.

I found a section in the manual which reads "this vehicle has a power-assisted brakes that assist automatically though normal use" - could that be it?

Any ideas idea? Car is only has 60 miles on it, so maybe it needs time to break in?
Good question @Dark5tar, it would be best to first search for any related threads / answers and if you don’t find any, create your own thread...This helps to keep threads on topic. Thanks! :)
 

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