Dangerous cylinder deactivation trouble on 2018 CX-5 and Mazda6 models

Unless "Cylinder Deactivation" is being completely deleted and Mazda is not saying anything.

Let's face it, vehicle manufacturers have done much worse in recent times. Does VW sound familiar?. :)

It's all about the bottom line, even if a few lives have to be lost in the process.

There is no reason to trust big business. They are not our "Friends".

I doubt Mazda disabled CD. That would violate emission footprint they already filed for and the advertised mpg on the window sticker. The mpg difference as some had noticed after the PCM update is more than the difference between CD and no CD. As a reminder:
2017 CX-5 FWD with no CD.....mpg=24/31(city/hwy)
2019 CX-5 FWD with CD.....mpg=25/31
 
I think it is possible to check the rocker arms using endoscope.
It is not easy but I checked it, you need to be patient.
I was using 8 dollar endoscope from ebay, but of course not 100% sure that I`ve reach and looked at correct arm though.

My model is M6 2,5 non turbo EU model from 2018.

However Mazda has not yet announced a service campaign in Europe !!!
Dealers know nothing about that.

I`ll check ECU version after 1st inspection at dealer to see if there are some changes :), anyway I`ve no limp mode, etc.
Now Forscan show version PYL3-188K2-E at Power Train Control Module.
Who knows, maybe EU version have different firmwares without a problem. Honestly I don`t think that this is possible, but we`ll see.
 
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My model is M6 2,5 non turbo EU model from 2018.

However Mazda has not yet announced a service campaign in Europe !!!
Dealers know nothing about that.

This is not true.

FYI, Mazda Germany has already started a service campaign (by letter, email), the German authority published a recall, and in my country you can call in and have the FW updated on simple request by your dealer (which I did 2 months ago), (I suppose before an official callback, but they are aware of a possible problem), and in Italy a service bulletin came out etc.

Please do not publish unverified facts here!
 
I could not find any information on the internet, I did not receive an answer from Mazda Germany, that's why I was wrong.
I`m living in Poland and here no info about that recall so I started to search outside.
I apologize for my disagreement.


It seems that in Poland this recall may start a bit later, but why Mazda Poland give me no info about that I don`t know.
 
Images of the damper in the transmission and S-HLA...
https://www.webcg.net/articles/gallery/38577
https://car.watch.impress.co.jp/img/car/docs/1116/453/html/022_o.jpg.html
https://car.watch.impress.co.jp/img/car/docs/1116/453/html/023_o.jpg.html

And here is an explanation of temperature control for deactivated cylinders (use google translate like I do if you can't speak japanese):
https://www.autocar.jp/wp-content/uploads/2018/03/mazda-cx5-2018_180330_06.jpg

Looks to have been plenty of good old fashioned Japanese engineering gone into this one.

I was initially very sceptical of the PCM software fix recall, however after reviewing everything I can get my hands on regarding the switchable HLA's, I now consider the possibility that there was an issue with released management software that was properly fixed more plausible...
It's possible that the rocker arm was dislodged due to bouncing or some other symptom of incorrect S-HLA oil pressure under certain conditions due to incorrect oil pressure at the S-HLA . It seems that this would be controllable from an oil control valve feeding this S-HLA.
 
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Mazda cylinder deactivation may be more perfect than we think, however, I am concerned about the situation where after some time of car use, for example, a hydraulic valve failure will occur.
On the other hand, Mazda needs to know what they`re doing and what the probability of valve failure. The valve itself has to be of very good quality.
Who knows, maybe patch in the software will be a permanent solution for CD. Here only time will tell the truth.
 
An oil control valve for cylinder deactivation opens an oil passage to the outside of the SHLA where the switch pin is, pushing the pins in and therefore deactivating the cylinder.
 
Automatic transmissions are full of oil control valves.. they can fail but usually only after many many km. So hopefully the same can be said for those used to control cylinder deactivation. I believe some variable valve timing systems use oil control valves too.
 
I doubt Mazda disabled CD. That would violate emission footprint they already filed for and the advertised mpg on the window sticker. The mpg difference as some had noticed after the PCM update is more than the difference between CD and no CD. As a reminder:
2017 CX-5 FWD with no CD.....mpg=24/31(city/hwy)
2019 CX-5 FWD with CD.....mpg=25/31

I had the reflash last week after my oil pressure warning light went on, the engine starting running very roughly and nearly stalled. I stopped, checked the oil (which was fine) and restarted the car. No oil pressure warning, no funny noises, so I continued driving. Called Mazda Experience and they set me up with a dealer appointment two days later. They let me know that I would still get a recall letter near the end of August, but to ignore it.

I didn't ask about the rocker arm issue, so I don't know if they looked. I assume they didn't. When I got the car back, it felt a little sluggish initially, but within a few miles it felt fine. I think that if the rocker arm was displaced, you would hear something or feel at least a slight misfire. My engine runs quiet and pretty smooth.

I think the CD is still working fine as well. Today I was travelling on level ground, light load, constant speed, and I noticed the MPG gauge jump from 20 mpg to about 60 and stay there until I hit a slight grade; then it started dropping. Same thing happened at steady highway speeds.
 
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smooth.

I think the CD is still working fine as well. Today I was travelling on level ground, light load, constant speed, and I noticed the MPG gauge jump from 20 mpg to about 60 and stay there until I hit a slight grade; then it started dropping. Same thing happened at steady highway speeds.

CD only improves, at best, 2 to three mpg.

I can assure you, the jump of 40 mpg had nothing to do with CD.

Welcome to the forum. It will behoove you to read up on any subjects that may be of interest to you. During the past couple of years, a lot of information has been shared on this subject plus many, many others.
 
CD only improves, at best, 2 to three mpg.

I can assure you, the jump of 40 mpg had nothing to do with CD.

Welcome to the forum. It will behoove you to read up on any subjects that may be of interest to you. During the past couple of years, a lot of information has been shared on this subject plus many, many others.

I think those in flight MPG readings should be taken with a grain of salt or in other words they dont mean much
Average at the end of a tankful is the best gauge
 
CD only improves, at best, 2 to three mpg.

I can assure you, the jump of 40 mpg had nothing to do with CD.

Welcome to the forum. It will behoove you to read up on any subjects that may be of interest to you. During the past couple of years, a lot of information has been shared on this subject plus many, many others.
Thank you for the welcome.

I understand that the average fuel economy is only up 2 mpg with CD; however, the mpg gauge clocks real time miles per gallon. As such, the mpg on the gauge varies greatly from 0 to 80+ mpg depending on load, speed, gear and grade, which, over time, creates the average fuel economy.

In my scenario, I was traveling maybe a quarter mile or so on level ground, at steady rpms and steady speed, when I saw the mpg monitor jump significantly until encountering an upgrade, where it dropped. My thought was since every other condition was equal, the only variable would be CD activation; demonstrating that CD was functioning after the reflash. That short but significant change in mpg would be part of the 2 mpg average improvement. Made sense to me.
 
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My model is M6 2,5 non turbo EU model from 2018.

However Mazda has not yet announced a service campaign in Europe !!!
Dealers know nothing about that.

This is not true.

FYI, Mazda Germany has already started a service campaign (by letter, email), the German authority published a recall, and in my country you can call in and have the FW updated on simple request by your dealer (which I did 2 months ago), (I suppose before an official callback, but they are aware of a possible problem), and in Italy a service bulletin came out etc.

Please do not publish unverified facts here!

There is no recall yet in many European countries. I've been contacting Mazda Sweden since the end of June to see if a new Mazda 6 could be reprogrammed before delivery on the 22nd July and they weren't aware of this problem, and their latest answer was that they would take action only if instructed by Mazda Japan. No recall in the UK as last week that I'm aware of. There isn't an entry on RAPEX as well which would be enough to force them to do something. This is just stupid since they are delivering new vehicles without reprogramming them and the rocker arm may fall before there is a recall, and since opening the valve cover isn't included in the recover... There is a recall in Romania and Austria as well so it's difficult to understand if the European Headquarters based in Germany have any role in defining a policy or if it is left to the representative in each country.
 
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I`ve already tried to contact Mazda from different countries in Europe.
They said "please ask your local distributor" and finally now there is no way to upgrade ECU in this car in Poland.


It is very strange considering that the fault may cause a sudden loss of power. You do not have to be outstanding to understand what the consequences may be.
 
I`ve already tried to contact Mazda from different countries in Europe.
They said "please ask your local distributor" and finally now there is no way to upgrade ECU in this car in Poland.


It is very strange considering that the fault may cause a sudden loss of power. You do not have to be outstanding to understand what the consequences may be.

The alert is finally on RAPEX therefore distributors in every EU country have to execute the recall:

Alert number:*A12/1226/19
Product:*Passenger car
Name:*3, 6, CX-5
Risk type:*Injuries
Category:*Motor vehicles
Brand:*Mazda
Type / number of model:*Mazda 3 (BP), Mazda 6 (GL), CX-5 (KF)
Type of alert:* Products with serious risks
Due to a software error, the powertrain control module (PCM) may operate improperly when transitioning from cylinder deactivation to full cylinder activation modes. As a result, an intake valve rocker arm may come out of position and make contact with internal engine parts.
This may cause the engine to stall in motion without the ability to be restarted, increasing the risk of an accident.
*
Measures taken by economic operators: Recall of the product from end users*(By: Distributor)
Description:*Passenger car under Mazda recall code: AK038A.
Batch number / Barcode:*The affected vehicles were manufactured between 7 November 2018 and 13 May 2019 (Mazda 3), between 26 March 2018 and 22 April 2019 (Mazda 6), between 20 June 2017 and 20 April 2019 (Mazda CX-5).
Country of origin:*Japan
Alert submitted by:*Romania
 
Hey guys!
I had my CX-5 taken to the service shop this morning. They took about an hour to work on the PCM update. They told me that the reprogram is complete and firmware has been updated. I do not see my trips reset or favorites lost on the infotainment, like most of them reported here of disconnecting battery before the update. Anybody else who had the same experience?
Did they actually do it? Any way to confirm this?
I don't see the firmware version on the invoice either... dang!

Thanks in advance.
2018 CX-5 Touring
 
Hey guys!
I had my CX-5 taken to the service shop this morning. They took about an hour to work on the PCM update. They told me that the reprogram is complete and firmware has been updated. I do not see my trips reset or favorites lost on the infotainment, like most of them reported here of disconnecting battery before the update. Anybody else who had the same experience?
Did they actually do it? Any way to confirm this?
I don't see the firmware version on the invoice either... dang!

Thanks in advance.
2018 CX-5 Touring

Mazda really should list the version on the invoice. Otherwise, people will be wondering forever if anything was actually done.

They've got to step up and do everything in their power to give people confidence in the fix.
 
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