2017~2023 AC enabled silently (not indicated on display) when temp control at coldest setting?

Sideswipe

Member
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2017 CX-5 GT AWD + Tech
I am 90% sure that when I have my temperature set to coldest (15C), the AC is turned on silently to achieve this temperature. By silently, I mean that the display does not indicate it's enabled.

I wouldn't necessarily object to the HVAC system enabling AC when necessary to achieve the set temperature -- it makes sense for it do so. But I do object to it not indicating as such, if that's what is happening.

The system is definitely NOT set to either "AUTO" or "DUAL". And unless I missed it, the manual doesn't state that this is expected behaviour.

Anyone have thoughts? I suspect the AC does in fact turn on, but it's a software bug preventing the display from indicating "A/C".
 

brillo54

Resident Curmudgeon
Contributor
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NE Indiana
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'16 CX-5 GT FWD
I've got a '16 (and US version) so I don't know if my observations apply 100% to your '17 but I'll chime in. I use the manual mode quite often with the temp turned down to 60F (15C). I keep it set the lowest so I don't get any heat and I have the AC turned off and I don't notice any cooled air coming from the upper vents or floor vents. However, if I use the split setting between floor and defroster or just the defroster (and I manually turn the AC off) it still feels like I have slight amount of AC going to the windshield. Could this be what you are experiencing?
 

7eregrine

The man, the myth, the legend
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Land of Cleve
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2016.5 CX5
By design in my experience. Whatever temp your ACC (automatic climate control) is on it will effect the airflow coming into the cabin that much when you click off. Hot or cold. To stop this, turn on recirculate.
 

PaulZooms

16.5 GT Sensing
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Lakewood, CO
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2016.5 CX-5 GT
I too have a US 16.5 (GT). If either the vents/mode are set to defrost, or the defrost button is depressed/lit, the AC runs without indication as you posited. How are these buttons set when you notice the unannounced cooling? Could it be outside air?
 
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2022 2.5GT
Why anybody has automatic climate control and overrides it is a mystery to me but if you do choose to do it that way just cycle the AC button. If you set it to auto and then select the lowest temp it will bring in and display the AC.
 
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2017 CX5 GT AWD Premium
I do not believe, if the AC button is not pressed and the temp control is set to the minimum temperature, that the AC compressor actually turns on. The system just allows the outside air in. If the temperature knob is set to a temperature higher than the outside temperature, the air will be heated though. The only time the AC kicks on is in defrost mode, regardless if the AC button is pressed or not.
 
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2017 CX-5 GT w/ Premium Pkg.
I've only noticed this during the winter when it's colder. I normally have my ac set to 68 degrees and when it's cold in the 40s or 50s the ac will blow warm air without me having to turn on anything. I've not noticed this much during summer months tho.
 

7eregrine

The man, the myth, the legend
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Land of Cleve
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2016.5 CX5
Why anybody has automatic climate control and overrides it is a mystery to me but if you do choose to do it that way just cycle the AC button. If you set it to auto and then select the lowest temp it will bring in and display the AC.
You're a pretty smart guy, not sure why you can't wrap your head around this. Sometimes I don't want the AC blasting out of the middle vents. Or the heat. These vents aren't really the most movable.
 
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2018 CX5 SE-L Nav+ 2WD 2.2D 150hp Auto
You're a pretty smart guy, not sure why you can't wrap your head around this. Sometimes I don't want the AC blasting out of the middle vents. Or the heat. These vents aren't really the most movable.

It would help you if you could switch off the middle vents. I don't think you have that facility on US/Canadian versions until recently. All I can say is the UK version has had switched middle vents since the beginning on all trim levels.
 
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2017 CX-5 GT AWD
My 2017 CX-5 doesn't even lower the fan speed to a reasonble level while in AUTO if making/receiving a phone call. High is too loud to have a phone call for me and most cars temporarily lower it during a call......
 

Sideswipe

Member
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2017 CX-5 GT AWD + Tech
I did some testing and am pretty sure that this ONLY occurs when I have the mode is on defrost or a combo of defrost + middle vents. The air coming out of the vents is definitely colder than the outside air.

This kinda makes sense, but still I think it really should indicate AC if the compressor is running.

I wonder if this has affected my mileage by some small amount...
 

7eregrine

The man, the myth, the legend
:
Land of Cleve
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2016.5 CX5
Thought this was already solved.
O yeah....
By design in my experience. Whatever temp your ACC (automatic climate control) is on it will effect the airflow coming into the cabin that much when you click off. Hot or cold. To stop this, turn on recirculate.
 

7eregrine

The man, the myth, the legend
:
Land of Cleve
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2016.5 CX5
You are expect far too much from Mazda.
My 2017 CX-5 doesn't even lower the fan speed to a reasonble level while in AUTO if making/receiving a phone call. High is too loud to have a phone call for me and most cars temporarily lower it during a call......
I've never heard of any car company doing this. So you would have to tie in the ACC with the status of the BT connection? Sounds complicated.
 
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'18 Mazda 6 Signature
OP: Defrost modes use A/C to dry out the air. So any defrost setting - whether A/C is enabled or not - will turn on the A/C. This is typical automotive HVAC operation.
 
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2018 CX5 SE-L Nav+ 2WD 2.2D 150hp Auto
My wife's 2012 enclave does flawlessly as well as my dads Malibu. Can't be that complicated. A quick google search shows most GM cars do this.

https://www.chevymalibuforum.com/fo...phone-via-bluetooth-cuts-air-conditioner.html

https://www.silveradosierra.com/climate-control/auto-fan-when-in-phone-call-t698072.html

Unfortunately, from the links you've provided, not everyone thinks it is a good idea.(dunno) I would rather keep cool (or warm). What if it's a long phone call? Here in the UK and Europe, now that Vauxhall/Opel have been taken over by the French (PSA Peugeot/Citroen) this facility (if it ever existed) would probably now break down...
 

7eregrine

The man, the myth, the legend
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Land of Cleve
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2016.5 CX5
Solution in search of a problem imo. Is it really that loud? How often is this a problem?
 
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2017 CX-5 GT AWD
Is it really a big issue, no, as I can just lower the fan speed if needed. I was just pointing a reason to 'Why anybody has automatic climate control and overrides it is a mystery to me' .......
 

Sideswipe

Member
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2017 CX-5 GT AWD + Tech
OP: Defrost modes use A/C to dry out the air. So any defrost setting - whether A/C is enabled or not - will turn on the A/C. This is typical automotive HVAC operation.

Thanks. This was total news to me! Now that I understand exactly what is happening, a google search tells me I'm not the only one wondering if/why this is happening. I see that most manufacturers illuminate the AC indicator in this scenario, and a small handful of vehicles actually allow override of this behaviour.

So I guess nothing to see here really, but why not indicate AC is on even if it can't be disabled in defrost mode by pressing the AC button? The HVAC system already does something similar by preventing vent mode change while in recirculate.