2010 M5 climate control temps

[Martyd]

We have only had our M5 a few weeks and today we got to test the climate controls. It's 92 deg here in CT today. Can't believe it. The AC did a pretty good job and I think I understand how to set the temperature. The ambient temp reading however is at least 9 deg off. Where is this sensor? The book says it may be off in extreme hot or cold, but 9 to 10 deg too low? Or the vehicle is driven at low speeds. On my Corolla the sensor is in the engine air intake. Works fine. My guess is the M5 sensor is in the climate control intake, too close the the cooled air.

I also wish I could change the vented air temp with the system off. It appears I have to turn on the fan, set the temp to hotter or cooler, and then turn off the system.

Also the system sometime wakes up in a different mode than how it was left. I'm keeping a log on how many starts it goes before a settings change. That's for the dealer.

Overall so far very happy with my Mazda 5. My wife also like the way it drives, so that's good news.

 

[mpvue]

I've been playing w/ the 'auto' settings on the HVAC lately also. I used to be suspicious of it, but it seems to work well. I haven't tried to compare if the ambient was accurate or not; what did you compare it to?
I've just been setting the temp to like 72* and leaving it there; if it gets comfortable, or a want to open the windows instead, I just turn the A/C off and lower the fan speed.

 

[coolmazda5]

The ambient temp sensor is behind the front bumper. My 06 has the old fashion dials and the 08 has the auto temp system. I don't really trust the auto one much to be honest but the ambient temp is always +-1 degrees according to the radio news, so +-10 might be too much, might be the sensor needs to be replaced on the next service?

 

[Snagjim]

I also wish I could change the vented air temp with the system off. It appears I have to turn on the fan, set the temp to hotter or cooler, and then turn off the system.

Also the system sometime wakes up in a different mode than how it was left. I'm keeping a log on how many starts it goes before a settings change. That's for the dealer.

Each manual control input will override the auto function for that control, but the other functions will still adjust automatically. If you want to run the system without the A/C running, press "Auto" then switch off the A/C. If you then want to turn the fan down, just adjust the fan manually. It's not explained well in the manual.

Sounds like there is a sensor problem for sure. On mine the ambient temp usually seems quite accurate.

 

[ljmattox]

Most of the good stuff's been said, I'll just add another data point.

My ambient temp reads within a couple degrees of what's reported (radio, bank signs, etc.) so that's fairly accurate.

I leave it on "auto" nearly always. It does cycle through modes as it decides what to do, based on (I think) a) is the engine warmed, b) interior temp, c) exterior temp. Def+floor, face+floor, face only, floor only can all get chosen based on its programming.

I like that I can switch off the A/C in winter, leaving it in "auto", and it "remembers" to leave it off the next time I start the car. IIRC my CX-7 was annoying in that regard.

So far, the only thing that catches it off guard are days like today: 42 degrees, but very blue-sky sunny. Auto temp set on 68. When I got back in after an errand, it was pretty stuffy-warm inside, but it took awhile for it to stop remediating the difference in outside temp and the dial setting (it was actually adding heat for a few mins) and start addressing the difference in *interior* temp and the dial setting (finally started piping in some cool air).

Otherwise, I think it works great.

 

[Martyd]

As usual the forum members have plenty of info. Thanks. I will try to get more familiar with the auto system. I have not used it yet and now that I know I can defeat the AC, which I don't use much, I'm more willing to play around with it.

If the outside sensor is behind the front bumper the readings should be pretty close. I used various sources that day (93 deg) and read 10 degrees cooler. I'll have the dealer check it out.