2019 CX-5, Coolant problem (CEL = P0126 )

This so called “engine coolant control valve” mentioned in the TSB is the “electrical thermostat” been implemented on the 2.5L along with newly added cylinder deactivation since 2018 CX-5. It’s served as the old mechanical thermostat functional wise for better control and efficiency. Unfortunately it also becomes a first-year problem just like the EPB on 2016 CX-5.

You should call MNAO directly and tell them this new engine coolant control valve should be covered like old mechanical thermostat under powertrain warranty, no ifs or buts.

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Now I'm confused.. are you saying there is no thermostat on the 2019 that looks like the image I added, and only this part that you mentioned?
 

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yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
Now I'm confused.. are you saying there is no thermostat on the 2019 that looks like the image I added, and only this part that you mentioned?
No, there’s no mechanical thermostat like your picture showed in your 2.5L. The “electrical thermostat”, or the engine coolant control valve used in the 2.5L with cylinder deactivation is getting more popular for modern engines. Toyota’s new Dynamic Force 2.5L uses electrical thermostat too.
 
No, there’s no mechanical thermostat like your picture showed in your 2.5L. The “electrical thermostat”, or the engine coolant control valve used in the 2.5L with cylinder deactivation is getting more popular for modern engines. Toyota’s new Dynamic Force 2.5L uses electrical thermostat too.
Sweet.. so I'm basically SOL unless Mazda covers this, and by the sounds of the guy At MNAO, he said that it's not likely mazda will cover this 100%, but maybe some..

Wait... So this IS the thermostat, they just renamed it essentially..
 
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2020 CX-5 AWD
This so called “engine coolant control valve” mentioned in the TSB is the “electrical thermostat” been implemented on the 2.5L along with newly added cylinder deactivation since 2018 CX-5. It’s served as the old mechanical thermostat functional wise for better control and efficiency. ….
You should call MNAO directly and tell them this new engine coolant control valve should be covered like old mechanical thermostat under powertrain warranty, no ifs or buts.

Unfortunately this situation is complicated by the fact that there is also a mechanical thermostat integrated into this coolant control valve. And I cannot find documentation on the operation of the valve, so it's unclear to me what the functionality of the mechanical thermostat is in the overall design of the valve.

So it appears that this Mazda stealership is trying to say the mechanical thermostat would be covered, but the valve is not. I agree with what you're saying, however it seems, based on the OP's case that they are relying on technical semantics to bail out on this warranty coverage. Time will tell where this ends up, but I would personally test the thermostat, regardless of anything else, because IMO it's very important to determine if it's working properly or not.
 
how is the thermostat even differentiated in this situation? I can't imagine a similar sized mechanical thermostat is inside the housing of this coolant control valve....
 
this makes no fkin sense. The thermostat is inside the coolant control valve. The thermostat is covered under warranty, but the control valve is not. How the hell does the dealer know based off of diagnostics that the problem is the control valve and not the thermostat specifically? I don't get it. Am I going crazy?
 
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2020 CX-5 AWD
… How the hell does the dealer know based off of diagnostics that the problem is the control valve and not the thermostat specifically? ….
As I posted previously, they didn't diagnose anything. The TSB says replace the valve, so that's what they're telling you.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
Unfortunately this situation is complicated by the fact that there is also a mechanical thermostat integrated into this coolant control valve. And I cannot find documentation on the operation of the valve, so it's unclear to me what the functionality of the mechanical thermostat is in the overall design of the valve.

So it appears that this Mazda stealership is trying to say the mechanical thermostat would be covered, but the valve is not. I agree with what you're saying, however it seems, based on the OP's case that they are relying on technical semantics to bail out on this warranty coverage. Time will tell where this ends up, but I would personally test the thermostat, regardless of anything else, because IMO it's very important to determine if it's working properly or not.
No, the electrical thermostat is a valve controlled by the traditional wax and electrical motor or purely a motor which opens and closes the valve. The motor is controlled by the car computer with precision software programming hence it gives better flow control than mechanical thermostat which can’t be controlled as wish by the car computer. Mazda’s engine coolant control valve is the thermostat. It’s a single piece part even if there’s a mechanical thermostat inside. The parts should be covered under powertrain warranty. I’d go all the way up to the highest level in MNAO if the rep says engine coolant control valve is not the thermostat.

Electronically Controlled Thermostats: A New Take On Wax And Brass
 
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2020 CX-5 AWD
… It’s a single piece part even if there’s a mechanical thermostat inside. ...
According to my FSM, the thermostat is a separate, removal part integrated into the valve, and instructions are provided for inspection and replacement.

Let me try this one more time - I am not disagreeing that they should cover this under warranty, just trying to explain how they are trying to duck out of it.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
According to my FSM, the thermostat is a separate, removal part integrated into the valve, and instructions are provided for inspection and replacement.

Let me try this one more time - I am not disagreeing that they should cover this under warranty, just trying to explain how they are trying to duck out of it.
Yes, I know. We’re trying to help the OP. Can you post the FSM on this coolant control valve?
 
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2020 CX-5 AWD
Yes, I know. We’re trying to help the OP. Can you post the FSM on this coolant control valve?
As mentioned in a previous post, I cannot find specific references to the coolant valve in my FSM, only the thermostat removal. And that removal documentation shows one of those stupid drawings, which does not clearly show exactly where the thermostat is coming from. They do have a section on coolant hose removal, which appears to be coming out of this coolant valve, but again the drawing is very poor, and I can't positively identify that it's actually the valve. I wish they did a better job with those drawings.

The coolant valve thing is all brand new to me as of yesterday and, as we all know, yesterday was a day where mundane things such as auto repair became quite unimportant. So I'm still trying to sort this out, and have looked at the valve on my own vehicle a couple times already, trying to get some clarification. What I've been able to see so far does not match the thermostat location of the drawing in the FSM. But the intake air assembly is blocking most of the view and I'm considering removing that stuff in order to get a better look. There's only so much that can be done with an inspection camera when access is so limited.

The only other source that appears to confirm the presence of a thermostat contained in the coolant valve is the link below of the part from a Mazda parts outfit. The description twice mentions thermostat, and I'm taking that to mean a separate, mechanical thermostat. But I'm not certain of that, and won't be until I can confirm it in some other way. I will report back once I get more information, unless someone else is able to find it first.


 
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Sent an email to the VP of the dealership. He called me and basically reiterated the fact that having it serviced outside the dealership really hurts my cause.. Unfortunately, he couldn't give me any information as to how the thermostat differs from the control valve. I kept telling him that this should be covered under the powertrain warranty since this coolant control valve is the new electronic thermostat.
He knows I have opened a case with Mazda, and he said he didn't want to muddy the waters...
 
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2020 CX-5 AWD
Sent an email to the VP of the dealership. He called me and basically reiterated the fact that having it serviced outside the dealership really hurts my cause.. …
This coolant valve thing that you're going through right now is disturbing in multiple ways.

First off, this stealership is saying that because they didn't make their expected outrageous profit from servicing your vehicle, that means they will not extend to you the 'good will' coverage that other owners get (I.e. the ones who did already empty their wallet at this outfit).

And we've already discussed the idea that this IS a thermostat, so it should be under powertrain warranty for that reason.

Next is the fact that Mazda is blindly just replacing this expensive part. No explanation of what the actual issue is that's causing the coolant flow problem, which means no indication if it might be possible to make some type of repair to the factory part - perhaps something a simple as cleaning out a blocked passageway, or repairing/replacing a defective electrical component.

And finally, there doesn't appear to be a part revision (that I can find anyway), which immediately raises the concern of this exact same thing happening again a year or two down the road, if the same part (which presumably has some kind of systemic defect) is used as the replacement.

Mazda is going to need to do WAY better on this problem, because what they've done up until now is unacceptable.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
As mentioned in a previous post, I cannot find specific references to the coolant valve in my FSM, only the thermostat removal. And that removal documentation shows one of those stupid drawings, which does not clearly show exactly where the thermostat is coming from. They do have a section on coolant hose removal, which appears to be coming out of this coolant valve, but again the drawing is very poor, and I can't positively identify that it's actually the valve. I wish they did a better job with those drawings.

The coolant valve thing is all brand new to me as of yesterday and, as we all know, yesterday was a day where mundane things such as auto repair became quite unimportant. So I'm still trying to sort this out, and have looked at the valve on my own vehicle a couple times already, trying to get some clarification. What I've been able to see so far does not match the thermostat location of the drawing in the FSM. But the intake air assembly is blocking most of the view and I'm considering removing that stuff in order to get a better look. There's only so much that can be done with an inspection camera when access is so limited.

The only other source that appears to confirm the presence of a thermostat contained in the coolant valve is the link below of the part from a Mazda parts outfit. The description twice mentions thermostat, and I'm taking that to mean a separate, mechanical thermostat. But I'm not certain of that, and won't be until I can confirm it in some other way. I will report back once I get more information, unless someone else is able to find it first.


These are what I’d found from online parts list.

Engine coolant control valve is #18 in the diagram:

Valve Water Control - Mazda (PYFD-15-16Z)

D2A996BA-9046-4146-9CBE-C34DC920D779.jpeg

If we go down to the engine coolant control valve part page to:

Other Names: Thermostat Housing, Water Inlet, Water Valve, Valve Water Control

It shows the coolant control valve is the thermostat housing, a part of thermostat system. And the location is the same for the mechanical thermostat found on the older 2.5L without cylinder deactivation.


Thermostat is #12 in the diagram:

Thermostat - Mazda (P502-15-171)

A19E2E36-0E73-4C4F-9E41-9D0158E9DC27.jpeg


Again, hard to tell where is the specific location of this mechanical thermostat on a 2.5L with cylinder deactivation.
 
:
2014 Ford Explorer Sport, 2009 CX9(Wife's)
If the engine does not have a mechanical thermostat, I would ask the dealer and/or MNAO what the function of this 'coolant control valve' is.

If it sounds anything like this, it's a thermostat and should be covered if you ask me.

noun
  1. a device that automatically regulates temperature, or that activates a device when the temperature reaches a certain point.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
The coolant valve thing is all brand new to me as of yesterday and, as we all know, yesterday was a day where mundane things such as auto repair became quite unimportant. So I'm still trying to sort this out, and have looked at the valve on my own vehicle a couple times already, trying to get some clarification. What I've been able to see so far does not match the thermostat location of the drawing in the FSM. But the intake air assembly is blocking most of the view and I'm considering removing that stuff in order to get a better look. There's only so much that can be done with an inspection camera when access is so limited.
Yes this coolant control valve is new to me too. And I just thought it’s an electrical thermostat used by many newly designed engines.

The only other source that appears to confirm the presence of a thermostat contained in the coolant valve is the link below of the part from a Mazda parts outfit. The description twice mentions thermostat, and I'm taking that to mean a separate, mechanical thermostat. But I'm not certain of that, and won't be until I can confirm it in some other way. I will report back once I get more information, unless someone else is able to find it first.

The description of the coolant control valve, PYFD-15-16Z, does contains thermostat.

Part Number: PYFD1516Z
Supersession(s): PYFD-15-16Z; PYFB1516ZA; PYFD1516Z
2.5 LITER 2018-20. 2.5 LITER NON TURBO. 2019-21. A kit containing a engine coolant thermostat and additional parts for installation. A valve used to control the flow of engine coolant to the heater core. Incl.Gasket,Housing and Thermostat. JAPAN BUILT. MEXICO BUILT. inlet. outlet. WATE. Engine Coolant Thermostat Kit. HVAC Heater. THERMOSTAT HOUSING.
 
"In getting up to speed on this, the coolant control valve which is failing is actually specifically only covered under the 3yr/36k mile warranty. That being said, we do have a case open with Mazda corporate on this. Like every manufacturer they need one open to consider any goodwill repairs. Where I can't make the final decision for Mazda, with you buying the car new, and being so close to the 36k mile mark I would be surprised if they didn't authorize the goodwill. I will keep you updated on this as soon as we hear back. Parts have been an issue for the last year because of the pandemic, factories are at limited capacity, which has really put a crutch on supply and the demand for automobile parts world wide."

- Email from Dealership President
 
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