Cx-5 2017 ac

[shadonoz]

I have had many Mazda's where the A/C compressor clutch is disengaged at WOT. I do not find it strange at all, just gives you less parasitic drag on the motor. Especially noticeable when you have a motor w/ around 100hp. If you are still WOT when A/C re-engages, you can certainly feel it.

There is even an error code for when the WAC system is malfunctioning...

P1460 MAZDA - Wide Open Throttle Air Conditioning Cutoff Circuit Malfunction

It DOES make perfect sense. It would even make sense to me if there was a "Half Open Throttle Air Conditioning Cutoff Circuit". I ALWAYS turn off the AC if I need max power, it's a HUGE parasitic drag.

Mazdadude, if there IS a WOTACCC, how could this happen: "If you are still WOT when A/C re-engages, you can certainly feel it." ? If it works, the AC wouldn't reengage.

I'm just looking for confirmation. Anchorman's AC pdf made no mention of a WOTACCC.

 

[mazdadude]

It DOES make perfect sense. It would even make sense to me if there was a "Half Open Throttle Air Conditioning Cutoff Circuit". I ALWAYS turn off the AC if I need max power, it's a HUGE parasitic drag.

Mazdadude, if there IS a WOTACCC, how could this happen: "If you are still WOT when A/C re-engages, you can certainly feel it." ? If it works, the AC wouldn't reengage.

I'm just looking for confirmation. Anchorman's AC pdf made no mention of a WOTACCC.

There is also a timer in the circuit that engages the clutch after a certain time. I'm not certain but it seems like it was around 5 or 10 seconds.

 

[Xeler8ing]

And anyway there is ALOT of stuff that isn’t documented.

Exactly. Just because one hasn't experienced it whilst others have doesn't mean it is garbage.

Lot's of "undocumented features" out there across different things. Everything can't be written down.

 

[Xeler8ing]

I do know that manually turning the A/C off made my 2001 Trans Am a wee bit faster. A modded Camaro and I faced off from a roll. They walked me by 1 car. Second go, I turned AC off manually, and I pulled them ever so slightly. Sure, anything can happen on the street, but I found it interesting and likely an indicator of the AC manually being off as superior for all-out mostest powa!

Indeed

 

[jthj]

I always trust empirical evidence over documentation. I work in IT and see documentation that’s flat wrong constantly. Or just missing information. The engineer who designed it almost certainly didn’t write the documentation.

 

[shadonoz]

I always trust empirical evidence over documentation. I work in IT and see documentation that’s flat wrong constantly. Or just missing information. The engineer who designed it almost certainly didn’t write the documentation.

So true. But no one has offered ANY evidence. Seat of the pants impressions and internet rumors don't qualify.

As an aside, I'm pretty impressed with the pdfs Anchorman has been generously sharing with us.

 

[Xeler8ing]

I always trust empirical evidence over documentation. I work in IT and see documentation that’s flat wrong constantly. Or just missing information. The engineer who designed it almost certainly didn’t write the documentation.

Yes but actual noticing of what is occurring can be considered as valid.

Sadly everything can't have empirical evidence behind it. Not possible all the time.

Anyway......

 

[Anchorman]

The PDFs that Mazda produce usually explain when you can expect any of the explained systems will not work so it would bullet point in a list that says the following conditions must be met. Ive read everything on the a/c and everything on the engine management and there is nothing to say it would be suppressed under hard or sustained acceleration. Ive also got large quantities of info from Toyota and they say the same. Ive also experimented with mine and here where Ive got the chance over several long and steep hill, there is not a hint of the a/c performance being inhibited.

Im not saying that there was never a car that didnt do it but Ive never come across one and I dont believe our Mazdas do.

 

[Xeler8ing]

The scenario I read was back in the very early 1990's about the then all new GM Holden Commodore. It was in the outback of Australia, 40 day, going at 110km/h and the motoring magazine tester/reviewer floored the GM Holden Commodore V6 to reach the max speed of 208km/h and then hold it there. The duration of time from memory was atleast a few minutes to reach maximum speed and then was held there for a few km. This was back in the day when there was no speed limits.

During this test, they noticed the air conditioning starting to blow hot air and not working as intended as power was being essentially diverted to maintain acceleration and velocity.

The above scenario in 99% of driving cases, will not be achieved by the average owner in normal day to day vehicle use. Even running short tests would more than likely not trigger it.

It should be noted exotica would probably not experience this scenario as they would be able to maintain air con temperature at high speeds and sustained acceleration.

"Do with it what you will"

 

[Xeler8ing]

I will say this. Air conditioning systems now should be different to what they were in the past. So it might not happen now but it did in the past.

I know I'll never know since I will never ever reach those speeds

P.S the above posted scenario I mentioned was pre-internet.

 

[jthj]

I think it’s sad if it doesn’t since the car is underpowered as it is and needs all the help it can get to accelerate not more parasitic drag.

However I’ve noticed it so I think it is managing it in the background to some degree.

What’s interesting is there is a note in the owners manual about how you need to monitor the temp gauge (that only is there on service screen) in heavy traffic and long hills to make sure the air conditioning isn’t overheating the engine. Shouldn’t the ECU prevent that ?

 

[Anchorman]

If anybody thinks it’s holding them back that much (which I doubt), there’s always an off button. It’s claimed that the compressor at full tilt can draw up to 5hp. Big deal.

I had that rental down to Key West where it was mid 90’s and the temp gauge never went above the half way mark, even crawling in traffic.

 

[shadonoz]

Whats interesting is there is a note in the owners manual about how you need to monitor the temp gauge (that only is there on service screen) in heavy traffic and long hills to make sure the air conditioning isnt overheating the engine. Shouldnt the ECU prevent that ?

In the old days, some cars' engines ran COOLER with the AC on due to the additional cooling fan on the radiator.

But YEAH, Shouldnt the ECU prevent that ? One would hope!

 

[Unobtanium]

If anybody thinks it’s holding them back that much (which I doubt), there’s always an off button. It’s claimed that the compressor at full tilt can draw up to 5hp. Big deal.

I had that rental down to Key West where it was mid 90’s and the temp gauge never went above the half way mark, even crawling in traffic.

I doubt its even a real gauge. Just an idiot marker like most of the rest. The only cars I've had with real gauges were not modern family cars.

 

[jthj]

I doubt its even a real gauge. Just an idiot marker like most of the rest. The only cars I've had with real gauges were not modern family cars.

Right hook up an OBDII scanner and you can read the actual temp.

 

[Anchorman]

.....and you’ll find it’s remarkably accurate. It’s the same information used by the engine management eco to control the engine warm up etc. There is no protection for the eco getting hot because the cooling system is considered capable.

 

[Unobtanium]

Right hook up an OBDII scanner and you can read the actual temp.

Yep. It frustrates me that this is not relayed to the driver with the gauges. Probably got tired of customers asking "is it normal if..." and decided to have the needle go to the middle of the gauge and stay the hell put, lol!

 

[shadonoz]

Yep. It frustrates me that this is not relayed to the driver with the gauges. Probably got tired of customers asking "is it normal if..." and decided to have the needle go to the middle of the gauge and stay the hell put, lol!

It could be that the gauge is accurately reflecting the effectiveness of the cooling system, so the needle stays where it's "supposed" to be.

 

[7eregrine]

Yep. It frustrates me that this is not relayed to the driver with the gauges. Probably got tired of customers asking "is it normal if..." and decided to have the needle go to the middle of the gauge and stay the hell put, lol!

So then you buy a car that...oh I dunno....has the features you want? Hehe [emoji1]

 

[Anchorman]

The 17 on (KF) models have a gauge.