| Gonzo |
I didn't see anything in the owners manual but I just noticed this during the past two days.
I have the heating set on Auto.... its been cold so the MO has been pumping heat to the floor. I looked at the heating system mode display only to find that the MO decided to then place the system into defrost and floor around 7°F.
Any ideas why... and why not right away? It was about the same temp the entire drive and made the mode change after about 20 minutes.
Odd. |
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| GripperDon |
| Sounds like an "Engineer" made some decisions when he programed the system, as to saving warmth for the engine, your feet, the windshield, etc. and your body. Hope he suited your preferences? Probable hard to do unless you get to experience the real conditions personally. |
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| Eric L. |
| Grip is correct. Once your interior temp reaches the desired setting, the auto climate control will switch to defrost/floor for heating and to keep the windshield clear. |
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| zebelkhan |
| I have a smoker friend who rides with me sometimes. To accomodate him, I roll down one of the windows a little bit and then take the system off auto and have the fan blow from the foot vent at max blast, with the idea that it will "scoop" the bad air and clear it through the window that is open. That works beautifully except that after a while, I guess when it reaches the temp setting on the display, it "automatically" switches the mode from foot to foot+middle vents! I then have to scramble to switch the mode back to foot level to keep the smoke from being blown into the back of the car. This is interesting because I have the auto setting off yet it still does that. :3: Go figure! |
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| GripperDon |
| Maybe the "Engineer" was a smoker and didn't think of that. :D |
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| zebelkhan |
| No doubt...and I bet the no no kind of "smoker" too. :2: |
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| senza |
| Can't use the "auto" mode in a cold climate because of the default to floor outlet ....you need air circulation immediately to windshield or visability "goes away" quickly.... |
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| Eric L. |
| Yes but even on defog (which is manual) sometimes after a long drive (after the interior temperature has reached the setting specified) the climate control will go back to auto mode in either the bilevel (face and feet) or heat/defrost (windshield and feet) modes. Strange! |
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| sctb1 |
| I set mine to auto, then press mode until it picks Defrost/Floor. This forces the system to always use that setting but the fan speed is still controlled automatically to maintain the desired temperature. The auto light is off. It was the same way on the previous 2 Maxima's I had. |
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| Eric L. |
| Yes but after a LONG time in defrost mode, it will switch back to auto even if you do not want it to. I found this out on a long drive, after about an hour in defog (and the cabin was all warmed up) the climate control suddenly changes back to auto. I get annoyed at it and switch it back to manual defog. |
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| zebelkhan |
quote:
Originally posted by sctb1
I set mine to auto, then press mode until it picks Defrost/Floor. This forces the system to always use that setting but the fan speed is still controlled automatically to maintain the desired temperature. The auto light is off. It was the same way on the previous 2 Maxima's I had.
So even when the auto light is off it is still on auto? I manually change the fan speed and the mode and it still switches on me when it wants to! I guess there is no "manual" mode at all. So why do we even have the "auto" switch?
The engineer must have been a "heavy smoker". :4: |
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| Nfilippelli |
i have a simple solution, don't let anyone smoke in your car!
its my standing rule, no one and i mean NO ONE smokes in my car.
hell i almost got into a fight with a friends dad who i was giving a ride. he kept insisting it would be fine, i insisted he didn't smoke.
finally i pulled over and said if he had to smoke so bad, he could
get out, smoke, and then get back in and we would continue.
Since it was freezing outside, and all, he gave up.
I cannot believe how stubborn people are about that.
Stupid smokers.
-Nick
quote:
Originally posted by zebelkhan
I have a smoker friend who rides with me sometimes. To accomodate him, I roll down one of the windows a little bit and then take the system off auto and have the fan blow from the foot vent at max blast, with the idea that it will "scoop" the bad air and clear it through the window that is open. That works beautifully except that after a while, I guess when it reaches the temp setting on the display, it "automatically" switches the mode from foot to foot+middle vents! I then have to scramble to switch the mode back to foot level to keep the smoke from being blown into the back of the car. This is interesting because I have the auto setting off yet it still does that. :3: Go figure!
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| zebelkhan |
Well, many people I know with real brains are smokers so they can't be stupid. Crazy...perhaps, but not stupid!
Getting back to the original issue though, is there any way to keep the auto feature from coming on? |
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| NatasG |
| I think all I do is hit the mode button to change to manual mode. My Mo seems to start up in the state I left it. Have your tried that? |
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| sctb1 |
| I think as soon as you set the fan speed it sticks with that and auto is off. |
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| Eric L. |
Yes its possible to use manual mode for an extended period. However, I have found when heating, once the cabin reaches the desired temperature, the system switches from manual to auto, even if you do not want it to.
Those who live in warmer climates may never experience this quirk. |
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| GripperDon |
| Another reason to :D |
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| senza |
| sctb 1 - I'll have to try that - set to "auto" and select "def/feet"... |
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| Gonzo |
quote:
Originally posted by Eric L.
Yes its possible to use manual mode for an extended period. However, I have found when heating, once the cabin reaches the desired temperature, the system switches from manual to auto, even if you do not want it to.
Those who live in warmer climates may never experience this quirk.
Odd I've never seen that.
Here is something to remember.....
Think of auto as "full auto" meaning when in auto it will control fan speed AND vent selector. If you move either one yourself it comes out of auto... (full auto) but will still continue to control the other mode that was not touched. If you manually select fan speed and vent selector than it will always stay there and it will NOT over ride that.
Make sense?
:4: |
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| GripperDon |
| Not address particularly to me , but make sense to me. It is basically the way I get auto temp but blowing where I want . |
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| Gonzo |
Me too.... I find that I use auto as it works good in these cold temps but manual turn off the AC. In the summer time I pretty much let the system run as designed.
The other item you could do is with the system off, press the mode button and you get fresh outside air without the fan. |
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| sctb1 |
quote:
Originally posted by senza
sctb 1 - I'll have to try that - set to "auto" and select "def/feet"...
That's what I do. Set it to 21 degrees auto, then mode it to defrost/floor and never touch it for the rest of the winter.
The other nice thing is if you need a blast of defrost to the windshield just press the front defrost button and it will switch to that and blast air. When you are clear just press the front defrost button again and it goes back to the def/feet mode with auto fan speed. |
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| GripperDon |
| It actually sounds pretty reasonable and well thought out. :) |
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| danielg280 |
| A similar, but related question: Is the system designed so that full auto always has AC on? Whenever I've used auto, no matter the season, temperature or humidity, the AC always comes on and always stays on. I would have thought it would be keyed to humidity in some fashion. |
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| GripperDon |
| Don't think their is a Humidity detector either relative or absolute, in the MO or for that matter any vehicle I know. They are notoriously inaccurate and difficult to maintain over a period of time, as least true for all electronic ones. The old wet bulb devices are accurate but not easy to use. |
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| Gonzo |
quote:
Originally posted by danielg280
A similar, but related question: Is the system designed so that full auto always has AC on? Whenever I've used auto, no matter the season, temperature or humidity, the AC always comes on and always stays on. I would have thought it would be keyed to humidity in some fashion.
If Nissan had it their way it they system should be used in AUTO all the time.... AC is on... The compressor will not operate at some temp... 25°F???? I forget. But you are right... if its 32°F out and the air is 10% RH... the AC will still be cycling. Crazy and a waste of engergy. I am always fighting with the MO to override the AC on feature when its not needed. At one point I was going to try to install a manual on/off switch for the compressor so I wouldn't have not have to try to turn off the AC when switching modes.
The AC is turned on when:
1. Auto is selected OR
2. Defrost is selected OR
3. Feet/Defrost is selected OR
4. Air Recirc is selected.
I thought I was losing my mind this morning... I had it in Auto with Defrost/feet and I was trying to select recirc (behind a sthinky car) and the MO wouldn't let me do it.... why why why.... then I realized the MO will not let you put it into recirc with when in any defrost mode... except when the fan is off if I recall correctly.
Somebody really put loads of thought into this.... I may not agree with it but I am impressed at the amount of thought. |
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| GripperDon |
| I was told that the MB system which does the same was following a federal law about recirculation (limits the time on) and the potential for build up of Carbon Monoxide fumes and oxygen depleted air in the cabin, both leading to drowsiness. |
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| special-k |
Ah yes, the wonderful incessant AC mode. :)
I was actually going to post about that but you all beat me to it.
On the one hand, I can understand why they make A/C default to ON for the defrost modes, as it helps take the humidity out of the air and defog faster/better.
On the other hand, I find it annoying that EVERY time I switch into AUTO mode I have to manually turn off A/C because I'm already getting pretty crappy gas mileage (averaging about 15 and I don't lead-foot :( ) and the last thing I need is anything else eating up gas! I can't understand, with all the intelligence in the MO's climate system, if it's 28F outside and I have the temp set to 68F inside, why does it insist on turning on the A/C compressor?!?!?! Grrrr...
:banghead: |
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| Eric L. |
quote:
Originally posted by Gonzo
Odd I've never seen that.
Here is something to remember.....
Think of auto as "full auto" meaning when in auto it will control fan speed AND vent selector. If you move either one yourself it comes out of auto... (full auto) but will still continue to control the other mode that was not touched. If you manually select fan speed and vent selector than it will always stay there and it will NOT over ride that.
Make sense?
:4:
I am fully aware of how the climate control system in the Murano works. That was why I was so surprised that the system will switch back into auto mode when it is in manual mode for a while. Yes I know everything thinks I am crazy, but I swear it is true (at least on my car). Here is the exact scenario:
Cold day (~15F) driving in humid winter weather (flurries) on the highway. Temp set to 70 both sides, and initially on AUTO mode. Since its so cold out, the system defaults to feet only. It begins to really snow, so I press the Front Defog switch, effectively overriding auto mode and switching to manual defog. The defogger blows full blast on the windshield. After a few minutes my windshield is clear so I turn down the fan to a more quiet setting and keep the defogger on. Now if switching from AUTO to Defog didn't switch off AUTO, turning down the fan definitely switches off AUTO. After the cabin reaches 70 degrees, the setting AUTOMATICALLY switches to defog/feet IN MANUAL MODE! I found this to be annoying since at that point not enough air was blown on the windshield to keep it clear, so I have to hit defog again. About 20 minutes later, same thing happens again. I can only surmise that once the comptuer senses the cabin temp = the set temp, it will fiddle with the climate control settings whether you like it or not.
I am not making this up. If you have not experienced it, then perhaps a) you haven't driven in the same conditions as I have, or b) I have a defective Murano. I am willing to accept both possibilities. |
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| Eric L. |
quote:
Originally posted by GripperDon
I was told that the MB system which does the same was following a federal law about recirculation and the potential for build up of Carbon Monoxide fumes and oxygen depleted air in the cabin, both leading to drowsiness.
Not sure if this was already posted, but the Murano's climate control system, when set to AUTO and RECIRC, will switch back automatically to OUTSIDE air after a set interval. (Not sure what that time is, but I noticed it on a cross country drive). I guess its to keep the driver from getting too drowsy breathing recycled air. |
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| GripperDon |
| Four posts up. auto recirculate cancel. |
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| Eric L. |
quote:
Originally posted by GripperDon
Four posts up. auto recirculate cancel.
Didn't see a post above regarding the automatic recirc/outside settings, but I do know from reading the owners manual you can hold either the outside air or recirc button, and it will blink to tell you its in AUTO or MANUAL mode (this is independent of the AUTO you see on the screen).
Never tried this, as it hasn't bothered me that it would switch to outside mode for a bit to keep me from breathing stale air. |
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| GripperDon |
| WOW the intriguing complexities of the climate control are amazing almost like the electronically controlled engine mounts. |
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| zebelkhan |
| I have the same issue as Eric L. I manually change the fan speed and set to fast, and change mode setting to floor vents. Now it should be in complete manual mode, right? But no...after a while, the mode setting automatically changes to floor+dash! Have not noticed any change in fan speed though. |
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| Eric L. |
quote:
Originally posted by zebelkhan
I have the same issue as Eric L. I manually change the fan speed and set to fast, and change mode setting to floor vents. Now it should be in complete manual mode, right? But no...after a while, the mode setting automatically changes to floor+dash! Have not noticed any change in fan speed though.
Yippee!! I was not imagining it. :D |
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| zebelkhan |
quote:
Originally posted by Eric L.
Not sure if this was already posted, but the Murano's climate control system, when set to AUTO and RECIRC, will switch back automatically to OUTSIDE air after a set interval. (Not sure what that time is, but I noticed it on a cross country drive). I guess its to keep the driver from getting too drowsy breathing recycled air.
I noticed this all summer with system on auto with A/C. The system always started in recirculation mode and after a while (when it cooled a bit) changed back to outside air. But it has not happened since its got cold and I am not using the A/C (I use auto but turn A/C off manually). |
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| special-k |
So.. there was a post saying that the compressor would not operate below 25F or something like that... which seems really crazy to have that temperature be the cutoff point.
Has anyone looked into whether or not the A/C compressor is really active if it's cold outside and you're warming the cabin or if the light just says it is? One thing I've noticed is the A/C compressor isn't noticable to me when it's on the way it always was in my american cars. When the compressor came on you could FEEL it and HEAR it. In the MO, I can't even tell the difference (no I'm not complaining :) ) Which makes me wonder... if the climate control system is in "heat" mode (since it knows what the inside, outside, and target inside temperatures are) does it simply shut off the A/C compressor? Except in the case of defrost mode when having the A/C compressor on makes sense, it just doesn't make sense to run the compressor for heating. Maybe the engineers thought of that too? On the other hand, I can see the benefit of having the A/C compressor on full-time, since doesn't the air not get the same filtration if it's not going through the A/C?
I'd be curious to know for sure what's going on there... if it only turns on the compressor for cooling or for defrost modes, then I would just (obviously) leave it on AUTO and stop worrying about shutting off the A/C all the time.
Thoughts? |
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| GripperDon |
quote:
Originally posted by special-k
So.. there was a post saying that the compressor would not operate below 25F or something like that... which seems really crazy to have that temperature be the cutoff point.
Has anyone looked into whether or not the A/C compressor is really active if it's cold outside and you're warming the cabin or if the light just says it is? One thing I've noticed is the A/C compressor isn't noticable to me when it's on the way it always was in my american cars. When the compressor came on you could FEEL it and HEAR it. In the MO, I can't even tell the difference (no I'm not complaining :) ) Which makes me wonder... if the climate control system is in "heat" mode (since it knows what the inside, outside, and target inside temperatures are) does it simply shut off the A/C compressor? Except in the case of defrost mode when having the A/C compressor on makes sense, it just doesn't make sense to run the compressor for heating. Maybe the engineers thought of that too? On the other hand, I can see the benefit of having the A/C compressor on full-time, since doesn't the air not get the same filtration if it's not going through the A/C?
I'd be curious to know for sure what's going on there... if it only turns on the compressor for cooling or for defrost modes, then I would just (obviously) leave it on AUTO and stop worrying about shutting off the A/C all the time.
Thoughts?
Maybe using the AC is a way of ringing the moisture out of the cabin air so the demisting of the windshield will be more effecftive. |
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| Eric L. |
I agree with Grip. I think the AC is on all the time just to keep the windows clear, even if its in heating or non defog mode. Yes I agree its not needed most of the time, but it certainly doesn't hurt anything other than fuel economy. Running the compressor frequently actually keeps its internal parts lubricated.
I noticed that unlike other Nissans, the Murano's AC compressor is a fixed capacity compressor. Other Nissans use a variable capacity compressor depending on how cold you want it.
As for air filtration, it makes no difference whether the AC is on or not, the air stil passes throught the evaporator core. The cabin microfilter is located in the HVAC ducts after both the heater and the evaporator core. |
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| special-k |
I understand, but I live where the relative humidity is usually below 30%. My windows don't fog much, only on the (rare) occasional rainy or snowy days. I just wish it was a selectable option... it's not a huge problem just a minor annoyance. I probably wouln't care except for the fact that, like I said before, I'm getting crappy enough mileage (about 15...) without running the A/C full time.
Does the A/C on the MO rob it's motor of power? On all my American cars it felt like it took about 50HP when the A/C was on. :) |
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| Gonzo |
quote:
Originally posted by zebelkhan
I noticed this all summer with system on auto with A/C. The system always started in recirculation mode and after a while (when it cooled a bit) changed back to outside air. But it has not happened since its got cold and I am not using the A/C (I use auto but turn A/C off manually).
Yes this is by design... if its really hot outside/inside the car the MO will try to cool it and it cools faster if its on recirc. After it hits about 4.5 bars or so (I can't remember) it will go back to drawing air from the outside. Cute idea. |
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| Gonzo |
quote:
Originally posted by Eric L.
Didn't see a post above regarding the automatic recirc/outside settings, but I do know from reading the owners manual you can hold either the outside air or recirc button, and it will blink to tell you its in AUTO or MANUAL mode (this is independent of the AUTO you see on the screen).
Never tried this, as it hasn't bothered me that it would switch to outside mode for a bit to keep me from breathing stale air.
Not quite... if you press and hold the fresh/recirc button eventually the lights flash and it will reset the system back into auto recirc mode.... oh my gosh... another form of auto mode!!! :headshake |
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| GripperDon |
| I swear this thing as they say in a certain movie "It's Alive" |
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