• Welcome to Mazdas247, the 24/7 Mazda Community and Resource. Learn about the benefits of becoming a Member here.
  • We're an Amazon Associate and eBay Partner. We earn from qualifying purchases.

Dangerous cylinder deactivation trouble on 2018 CX-5 and 6 models

ColoradoDriver

Gen-1 Kodo Design
Contributor
:
Denver, CO
:
2014 CX-5 Touring
Yikes, really sorry to hear of your problem OP. As someone who regularly pushes high RPM's accelerating, or going into manual mode (I don't have a sport mode in my 2014), this limp mode sounds downright dangerous and scary, and quite frankly I'm not sure I'd want the car anymore if it kept doing that. I hope wherever this leads and whatever you decide, that Mazda ends up making it right.

So, just reading the posts, I will admit I don't fully understand what all these parts are. Is it safe for me to say the cause seems to be this rocker arm (I'm sorry I don't know what that is) is falling off, and the the CD screws with the oil pressure and creates the perfect environment for when you push to high RPMs, it goes into limp mode? Sounds like CD in and of itself while contributing to this happening, isn't the actual root cause. The faulty arm and/or design allowing it to fall off to begin with is. So while Yrwei is quick to call this a CD issue, would it be possible for this to happen without the CD? Does the CD just end up creating the right environment for this to happen? I guess what I am getting at is if a 2.5L SkyActiv NA without the CD (Gen 1s, and 2017's) also had this rocker arm fall off, would they never know? Seems odd.
 
Last edited:
Yikes, really sorry to hear of your problem OP. As someone who regularly pushes high RPM's accelerating, or going into manual mode (I don't have a sport mode in my 2014), this limp mode sounds downright dangerous and scary, and quite frankly I'm not sure I'd want the car anymore if it kept doing that. I hope wherever this leads and whatever you decide, that Mazda ends up making it right.

So, just reading the posts, I will admit I don't fully understand what all these parts are. Is it safe for me to say the cause seems to be this rocker arm (I'm sorry I don't know what that is) is falling off, and the the CD screws with the oil pressure and creates the perfect environment for when you push to high RPMs, it goes into limp mode? Sounds like CD in and of itself while contributing to this happening, isn't the actual root cause. The faulty arm and/or design allowing it to fall off to begin with is. So while Yrwei is quick to call this a CD issue, would it be possible for this to happen without the CD? Does the CD just end up creating the right environment for this to happen? I guess what I am getting at is if a 2.5L SkyActiv NA without the CD (Gen 1s, and 2017's) also had this rocker arm fall off, would they never know? Seems odd.
The cause of the rocker arm falling off is low oil pressure on the lifter during cylinder deactivation. This is due to the wrong programming in the PCM. My dealership told me that they were informed by Mazda that they had two suppliers of this PCM and one of the suppliers had the wrong program on theirs. If you have a 2106 CX-5 you do not have cylinder deactivation and I would say you have nothing to worry about.
 

ColoradoDriver

Gen-1 Kodo Design
Contributor
:
Denver, CO
:
2014 CX-5 Touring
The cause of the rocker arm falling off is low oil pressure on the lifter during cylinder deactivation. This is due to the wrong programming in the PCM. My dealership told me that they were informed by Mazda that they had two suppliers of this PCM and one of the suppliers had the wrong program on theirs. If you have a 2106 CX-5 you do not have cylinder deactivation and I would say you have nothing to worry about.
Ah....that makes sense. Thanks for the clarification.
 
The rocker arm falling off is in Mazda Service Alert No: SA-15/19 Issued 04/08/2019

https://static.nhtsa.gov/odi/tsbs/2019/MC-10159203-0001.pdf
Thanks for this info t.suv. So again I ask why is there no recall. My vehicle had this issue back in October of 2018. This bulletin is dated 4-8-19. And I know that my vehicle was number 19 that they knew of then. By the time I got my vehicle out of the shop they knew of 26 that had experienced this issue. Who knows how many now that have been reported? And who knows how many are out there with the issue but they haven't discovered it yet?
 
:
2013 Mazda CX-5 Sport FWD Auto
Damn. Just changed the oil and rotated the tires on my mother in laws 2018. Wish I had read this thread and test drove/ floored it for grins and giggles. About ~12k on her odometer with primarily city driving. Not sure if she ever gets the opportunity to drive more spiritedly.
 

shadonoz

SkyActiv Member
Contributor
:
State of Jefferson
:
2017 CX-5 GT AWD+
The rocker arm falling off is in Mazda Service Alert No: SA-15/19 Issued 04/08/2019

https://static.nhtsa.gov/odi/tsbs/2019/MC-10159203-0001.pdf
Thanks for posting that.

Debris and contamination? The plot thickens.

REPAIR PROCEDURE

1. Remove the valve cover and inspect for any rocker arms that are broken or have fallen off, especially inthe cylinder deactivation area (cylinders 1 and 4). Refer to SA-041/18 if found.

2. Remove the front and rear oil control valves for cylinder deactivation and inspect the oil control valvesand cylinder head port for contamination or debris (see photo).If contamination or debris is found, photograph your findings and place the solenoid and debris inseparate plastic bags for collection. Mark on each bag the location where contamination was found,then contact Hotline for instructions on creating a case where you can attach the photos
 
:
2018 CX-5 Sport
Here is my Service report from them changing my engine
I now believe you now, thanks for that image. I agree, it should be a recall for all models with the faulty CD/PCM setting. And if they can't identify the ones with the bad PCM setting then all of them need to be recalled.
 
Last edited:

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg. Plano, TX
Contributor
:
Plano, Texas, USA
hopefully you guys can open that so all of you doubters out there will understand this is not a joke. I sincerely hope none of you have to experience this. I can't emphasize enough how important this is. You may be driving around with this problem as we speak. the only way you will know is if you get the RPMs high enough and maintain them for a bit. If the rocker is off your car will go into limp mode. They will need to reflash your PCM to the correct logic and obviously address your engine issue.
Thank you to all of you out there who have been believing me and backing me up.
Your repair invoice should silent those doubters right there. The service alert document from NHTSA should further prove there's a major issue on Mazda's cylinder deactivation system. I'm glad my hunch was correct and changed my mind getting a new 2018 CX-5 purely because Mazda suddenly added this problematic cylinder deactivation feature to its NA 2.5L starting MY 2018!

Here is my Service report from them changing my engine
The rocker arm falling off is in Mazda Service Alert No: SA-15/19 Issued 04/08/2019

https://static.nhtsa.gov/odi/tsbs/2019/MC-10159203-0001.pdf
 
I now believe you now, thanks for that image. I agree, it should be a recall for all models with the faulty CD/PCM setting. And if they can't identify the ones with the bad PCM setting then all of them need to be recalled.
MyFirstMazda I am glad you believe me now. Thank you.
 
Your repair invoice should silent those doubters right there. The service alert document from NHTSA should further prove there's a major issue on Mazda's cylinder deactivation system. I'm glad my hunch was correct and changed my mind getting a new 2018 CX-5 purely because Mazda suddenly added this problematic cylinder deactivation feature to its NA 2.5L starting MY 2018!
yrwei52 I believe you made the right choice in not buying the 2018. Mine is on a 3 year lease with 2 years remaining. I have tried to get out of the lease by moving up to the new CX-5 reserve with the Turbo at the same dealership that I bought the 18 at but it is going to cost me an arm and a leg to get out of it. So I wait for a couple years and hope that the new engine and PCM actually fixes the problem. So far so good but we will see. If nothing else I would like to see Mazda at least change the logic that puts the car into limp mode at those higher RPMs. That may make the car safer at least. But I have argued that point ad nauseam with Mazda and can't seem to make them change it.
 
:
2017 Mazda CX-5 GT, 2016 Mazda6 iGT, 2014 Mazda3 sGT hatchback
When there are enough complaints about endangered driving on NTHSA website,
NTHSA will open an investigation, which might lead to a recall.
Or, Mazda could issue a safety recall voluntarily. We will see about that.

I have current 3 Mazdas in my household. None has any problem for 2-5 years.
(own a '08 CX9 which also had 1-2 minor issues only)
Mazda are very adventurous in engine technology. Skyactiv-X is one good example.
There new technologies, big or small, could lead to problems with poor test coverage.
i-eLoop is another example. Expensive replacement of battery (>$400-500) with very marginal gain in MPG.
I am sure Mazda will address this problem per se quickly, if they can find a good solution. (cheap and effective)
They also ran into problem with the Skyactiv-D oversea. For that one, I don't think Mazda has a good solution (repair-wise).
Personally, I will avoid it (was looking forward to it for years) until Mazda proves itself that it is truly fixed.
 
I asked the Mazda dealership to disable CD on mine when they installed the new engine and they said they couldn't do that. So dang frustrating!!!
 
:
2013 Mazda CX-5 Sport FWD Auto
Was looking at the Honda thread about their variable cylinder management system and people disabled it https://www.odyclub.com/forums/52-2005-2010-odyssey/268778-vcmuzzler-ii-disabling-vcm-faq-s.html
Im one of those peeps. I bought the cheaper VCMTuner that is composed of a simple adjustable resistor and OEM connectors. Van drives nice and smooth now. Dont have to worry about misaligned piston rings, fouled spark plugs, failed catalytic converter, motor mounts prematurely failing, etc. The potential consequences to Hondas VCM system operating over the lifespan of the van are a friggin nightmare.
 
:
2017 Mazda CX-5 GT, 2016 Mazda6 iGT, 2014 Mazda3 sGT hatchback
Actually, CD is a turn-off to me.
Complication for nothing significant.
I am glad that the Skyactiv-G-turbo does not have CD.
Anything big issue with the G-turbo?
That is what I would like to know if any.
 
Top