Winter is here and my CX-5 turbo is now a 2.0L!

There was a cold weather performance issue on earlier 2.0 skyactivs. I think they were going into a partial limp mode because of a faulty sensor or programming.

Please do share what you can if you find something. This isn’t a minor issue that Mazda should be hiding.

I remember getting the TSB done on the 2.0 CX-5 and no issues with it.....can't recall getting it done for 2.5 Mazda6 though which sometimes get a check engine light with code p3000 (which I easily erase via Torque Pro) when sometimes starting cold engine at temps 50-60 degrees outside....our version of cold lol. I think its related to
TSB #01-007-19-3541

...which is for all skyactiv vehicles.
 
Gotta admit, it is confusing to say the least. Why would they do this for traction reasons, in an AWD vehicle and not a FWD vehicle? Why only on the 2.5T? It seems to me that the engine running cold would be the determining issue, whatever it may cause.
 
Just an observation that if it is for safety and traction, it’s illogical for Mazda to program it like this because roads can be iced over when it’s in the 30s, yet power isn’t reduced.

If you read earlier in this thread and in all other previous threads on this subject, the going opinion is that the power is being choked back to protect us from ourselves when there may be ice on the roads because it's cold outside. I've commented before that the theory makes no sense because it's choked back somewhere under 20°, when freezing = 32°.

Regarding "Other manufacturers might be able to mitigate whatever this issue is through other ways (or might not have to deal with it at all)" Other manufacturers are mitigating nothing. There is no issue to mitigate. There never has been an issue in the history of turbo cars. Other turbos universally excel in cold weather, while Mazda has not only stopped this one from getting sportier, it has intentionally choked it back.

If there's an issue to mitigate, Mazda is the first one to ever see it.

This is a legitimate significant complaint (as are the seats and other issues discussed here). I don't see why discussion on this specific conversation gets shot down like this.

I found this, which is the only thing I could find that might somehow relate to the 20F cutoff in the CX-5.


"A 10-percent salt solution freezes at 20 degrees Fahrenheit (-6 Celsius), and a 20-percent solution freezes at 2 degrees Fahrenheit (-16 Celsius)."

Some turbos do seem to have issues with the cold. Uno brought up the Subaru WRX owners who experience a boost cut due to overboost in cold weather on page 8. I don't know if this is the same thing, though.
 
Some turbos do seem to have issues with the cold. Uno brought up the Subaru WRX owners who experience a boost cut due to overboost in cold weather on page 8. I don't know if this is the same thing, though.

Mazda did a similar thing with the Mazdaspeed engines. They use load based tuning on the Speeds and when a certain load level/threshold is reached, they do a boost cut or (was it a fuel cut) to avoid blowing up the engines. This is notable in cold weather because as we all know, cold weather makes turbocharged engines more potent and the Mazdaspeed engines can produce a lot of torque. Maybe this is what is happening on the 2.5T CX-5 engines, that or it is a traction issue. We need more data though to verify.
 
I never noticed any boost cut in my 07Speed6. It was all stock, but the only time I had reduced power was on snow/ice when traction control kicked in. Most of the time if I was driving on snow in the winter, I turned off traction control. I had winter tires, so it just gripped and ripped.
 
Some turbos do seem to have issues with the cold. Uno brought up the Subaru WRX owners who experience a boost cut due to overboost in cold weather on page 8. I don't know if this is the same thing, though.
Thanks for that.

I completely overlooked it.

There were posts dating back a few years on another model Mazda that had this issue. I came across them a while ago when this subject was first raised. I believe it got resolved by Mazda.

I forget what model it was...I'm not conversant in the brand.

I'll see if I can dredge them up.
 
I never noticed any boost cut in my 07Speed6. It was all stock, but the only time I had reduced power was on snow/ice when traction control kicked in. Most of the time if I was driving on snow in the winter, I turned off traction control. I had winter tires, so it just gripped and ripped.
You didn't notice it most likely because you were stock. The issue manifested on Speeds with mods that were still running the stock tune. But the cold weather does have an effect on it. I remember hitting 19-20 psi on my Speed3 with the stock tune and only a stage 2 intake and catback exhaust as my mods, all because of the colder weather. Since they run on a load based tune, there are no boost limits which allows the engine to end up hitting higher boost than usual.
 
If Mazda has some limitations intentionally built in to the tuning I would guess it is somehow to protect the engine.

I haven't read anything on this thread that indicates what is being 'dialed back'. There are lots of possibilities. Is it some kind of turbo 'lag'? I guess that is programmable but could it also be thick oil in the turbo?

Maybe even Mazda doesn't know? Did they resolve this issue on the other vehicle mentioned? If it's going into a 'limp home mode' with only limited power available that could be pretty bad in traffic.
 
Actually had this same issue in my '15 Sonata Eco. Has a small 1.6t that was much less powerful in the winter. Was noticeable because Hyundai tuned that engine to make peak torque all the way from 1500 to 4000 RPM. Have noticed this a little bit in my CX5 but doesn't make it a complete dog. Just not quite as peppy.
 
Man, I just scrubbed the forum on a search for "turbo" as well as "turbo cold power" and cannot find the posts I recall seeing before.

Can someone give me a list of Mazdas that have turbos? I'll search each individual forum by hand. I know I've seen this issue discussed in another model from posts of (as I recall) at least a few years ago.
 
Okay, I found the December 2008 thread I was thinking about in the Mazdaspeed3 forum:

We All Know About the Cold Weather Boost Cut, But...

The OP's initial post begins with:
I know that it is common knowledge about the cold weather boost cut. My question is why??? Turbo'd engines are supposed to run more efficient in colder weather, right? If anything, I could understand a boost cut in hotter weather as the turbo's could cook themselves if boosted too hot.

This comment seemed to be the most salient explanation of the behaviour.

No discussion of Mazda or factory communications or possible resolutions were had. And this was 11 years ago.
 
^^ Yeah, I think that thread was mentioned previously, maybe in shadonoz's thread about the same issue. I wonder why this wasn't such a hot topic back then? Maybe because there were so few Mazdaspeeds sold? Or maybe because there are tuning/aftermarket options for the Speed3 and Speed6?

Other turbocharged non-rotary Mazdas - CX-7, Mazda6.
 
Okay, I found the December 2008 thread I was thinking about in the Mazdaspeed3 forum:

We All Know About the Cold Weather Boost Cut, But...

The OP's initial post begins with:

This comment seemed to be the most salient explanation of the behaviour.

No discussion of Mazda or factory communications or possible resolutions were had. And this was 11 years ago.

Now that is some great detective work, Deer!

I do follow the logic - cold air is denser therefore more air flows through the MAF (Mass Air Flow Sensor). When a certain limit is reached (as described as voltage) the MAF triggers a signal to the ECU (Electronic Control Unit - aka car's computer) to kill the boost. I assume it kills the boost by either by cutting fuel delivered to the engine or possibly bypassing the turbo via waste-gate?

This theory has an added value because it could account for inconsistencies as humidity might factor into the MAF accounting as well as outside temperature.

Now the follow up questions are: Why kill the boost? Is it because the fuel pump/injectors can't keep up? Or is it if the ECU allowed/was able to handle the denser air/fuel would the over-boost harm the engine?

Lastly, as a disclaimer please don't take my musings as fact. It is just an opinion formed based on the information provided here to possible help further the discussion. I can be 100% waaaaay off base. As they say, even a wrong opinion might help find the right answer. :)
 
I'd argue that something wasn't designed properly if it cannot accommodate/control the power at various temperatures straight from the factory.

If it's an overboost/boost cut/fuel cut issue, I would expect a check engine light to turn on or flash, but maybe they 'disabled' it for this issue to prevent a large number of complaints.

Speaking of overboost/ boost cut/fuel cut, does anyone have any input on what happens? I've never experienced any of those. When it occurs, if you keep your foot in it, does the power come back or do you have to let off and reapply throttle?

And again, as others have said, all speculation/opinions at this point.

I'd really like to see some data (boost, throttle position....etc) to maybe shine some light on this. If it were a normal winter in MN, the locals with this issue could test, but we've been 'stuck' with above normal overnight low temps(~20 degrees).
 
I've been suggesting all along that the root cause of this behavior is timing retardation based on MAF readings. It's just an overly aggresive protection mechanism for the engine. Higher air density means you can get a lean condition unless it is compensated for, which is important to prevent in any engine but especially in turbocharged ones. Mazda would rather throw a wet blanket on the performance of the motor rather than risk more warranty claims. What I take issue with is how aggressive it is in these cars. It's normal for an engine to retard timing a little bit in the name of running safely, but the Skyactiv engines do it so much it feels like a limp home mode in the most extreme cases.
 
I'd really like to see some data (boost, throttle position....etc) to maybe shine some light on this. If it were a normal winter in MN, the locals with this issue could test, but we've been 'stuck' with above normal overnight low temps(~20 degrees).

There are two irons in the fire on meeting that desire:

-Unobtanium is gonna have his car put on a dyno when equipment availability intersects with proper weather conditions.
-Someone else commented that his dealer's shop is also going to investigate this at the nuts & bolts level when conditions are right.

I still wonder if an ECU tune would override this factory programming.
 
I'd argue that something wasn't designed properly if it cannot accommodate/control the power at various temperatures straight from the factory.

Well, they did take the engine from the CX-9 and drop it into the Mazda6, then the CX-5. I'd say that the engine is right at home in the CX-9. Maybe the issue is that they didn't detune it for the 6 or the CX-5, and instead detuned it by cutting/restricting power in temps below 20F.

If it's an overboost/boost cut/fuel cut issue, I would expect a check engine light to turn on or flash, but maybe they 'disabled' it for this issue to prevent a large number of complaints.

Yeah I thought this might be the case too. I mentioned that possibility in one of my replies to you on page 11.

Speaking of overboost/ boost cut/fuel cut, does anyone have any input on what happens? I've never experienced any of those. When it occurs, if you keep your foot in it, does the power come back or do you have to let off and reapply throttle?

After a quick google search, I found this post on supraforums that details boost cut/fuel cut. I'm not sure if this is what's happening on the CX-5. It seems to be more like boost "reduction", or something similar to this phenomenon discussed on iwsti.
 
At what RPM is this happening? What gear? To trigger this MAF voltage issue, you have to be at high RPMs for the intake to be really ingesting so much air that it trips up the MAF sensor.

A boost cut/fuel cut would feel like hitting something invisible in front of the car. Usually on WOT acceleration, you'll get pushed back to your seat. If a boost cut/fuel cut happens then, your head will bob/jerk forward noticeably. A similar feeling is shifting to a higher gear while you're at full boost, the shift will cut off power and your body will inevitably jerk forward as a response.

I really wish someone would be able to do a datalog while this is happening on their cars. As it is right now, to me it seems unlikely that is a real issue with turbo CX-5s.

However, it makes no sense to me that a number of users in this thread are complaining about the same problem, especially since they own turbo CX-5s. So there is something going on. And since I might be looking into a turbo CX-5 in the future, I am hoping this gets resolved soon. I don't think it will stop me from buying one, but I would feel better if this was resolved.
 
Has it been a lack of cold temperatures recently that have kept those who have had the problem data log it?
I doubt I’ll see temps cold enough where I live to experience the problem.
 
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