 |
 | Home | Contact Us | FAQ | Search & Site Map | Link to Us |
 | Sign In | Join | Other 45 Sites in Network |
Car Forum / BMW Cars / September 2006E46 AC - does it always runs in recirc mode?
I posted this three weeks ago but it never appeared on my News Server, although it did appear on Google Groups. But I didn't receive any responses, so I'll give it one more try. Does anyone know if the E46 Car/Key memory setting called "Cooling output", which is set by default to "hot country" on cars for North America, controls the recirc damper setting as well as other flaps? As soon as the AC button is pressed, the intake switches to recirc, which decreases the airflow to the rear seat area and also makes the air noise markedly louder. If the car/key memory is changed to "normal" and this allowed fresh air to be cooled, these problems would be eliminated. When getting into a parked hot car, the recirc button could still be used for rapid initial cooling. Before I pay the dealer to make the change, I am trying to get a better idea of what this setting does, besides closing the footwell and defrost vents. (http://www.bmwnation.com/tech/glossary/tech_carkeycfg_1999.html) By removing the cabin air filter, I can see the recirc dampers closing off the fresh air inlet when the AC button is pressed, just as they do when recirc is pressed. I don't understand the problem. When you get into a hot car and switch the AC on, AND you want max cooling, you have it because the car has selected it for you. Once the car is cooled, you switch to normal mode if you want it. You are suggesting that you turn the system on in Normal, then select Recirc if you want it, then select Normal again after the car is cooled the way you like it. The car is demanding a single button press, you are asking for at least two. If pressing a button is problematic, then the car wants the least number of button presses already. Personally, I prefer to ALWAYS make this choice -- Normal or Recirc -- but if the car made the initial call on what should be selected, a simple button press would not annoy me. >I posted this three weeks ago but it never appeared on my News Server, >although it did appear on Google Groups. But I didn't receive any [quoted text clipped - 20 lines] > dampers closing off the fresh air inlet when the AC button > is pressed, just as they do when recirc is pressed. I live in a temperate climate,and I rarely get into the car and want max cooling, Jeff. I normally leave the system in manual mode (floor vents on and face level vents on) with the fan speed of my choice, to keep the system from blasting me out of the car with full fan speed. I assume this is what you mean by normal mode. This isn't Phoenix-weather here! I didn't mean to imply that I select Recirc manually. I rarely do, unless following a noxious diesel. The problem is, as soon as I press the AC button to get additional cooling, the system goes into recirc and can't be over-ridden. It simply doesn't matter whether I select fresh, recirc, or auto recirc. With the exception of the fixed recirculating air, I get what I want with a single button-push - AC on or AC off. That said, I have been out experimenting with the settings again, and I now find that upping the temperature setting a few degrees with AC on allows the recirc flaps to open allowing normal airflow to resume. So I suppose it is simply a matter of remembering this counterintuitive step and putting up with slightly warmer footwell air. Whether the number of degrees I have to add is dependent on the actual cabin temperature remains to be seen. If I have to move it up to 80 on a hotter day, I suspect the footwell air will become much warmer than comfortable even with the AC on. But this workaround is a help in 70 degree weather. > I don't understand the problem. > [quoted text clipped - 35 lines] >> dampers closing off the fresh air inlet when the AC button >> is pressed, just as they do when recirc is pressed. >I posted this three weeks ago but it never appeared on my >News Server, although it did appear on Google Groups. But I [quoted text clipped - 20 lines] >dampers closing off the fresh air inlet when the AC button >is pressed, just as they do when recirc is pressed. Don't know if the e46 system is smart enough to do this, but recent vintage HVAC systems will switch to recirc mode if the system senses very high cabin temps. Particularly applicable when starting the car after it's been cooking in the sun. When the cabin temp then drops far enough the system will allow the fresh air intake to open. If, otoh, your e46 is always in recirc mode, even after the cabin has reached a reasonably cool setting, one can surmise a fault in the controller or one of the temp sensors could cause the behavior your seeing. That you can see the actuator moving the damper means the actuator is not the fault, so the problem is upstream somewhere... /daytripper '00 s4 6spd I have now found that advancing the system's temperature setting a few degrees above the minimum allows the vents to reset to Fresh Air. Not perfect but better. >> I posted this three weeks ago but it never appeared on my >> News Server, although it did appear on Google Groups. But I [quoted text clipped - 35 lines] > /daytripper > '00 s4 6spd >I posted this three weeks ago but it never appeared on my News Server, >although it did appear on Google Groups. But I didn't receive any [quoted text clipped - 20 lines] > dampers closing off the fresh air inlet when the AC button > is pressed, just as they do when recirc is pressed. When it is very hot the AC starts in recirc mode to cool the car down more quickly. Once the cabin has cooled a bit and you have got moving (so the ambient air under the bonnet / hood is cooler than it would be if the car has been standing in the sun, then it will change to external. Also check you have not got the switch down. Recirc is OK for short periods, but on a long run the air in the cabin will get stale. I did this accidentally once after passing a treatment works. 100 miles later I was nodding off, until I noticed I had left it in recirc by mistake. Mine does not change to external, no matter how long it has been running. And it does not respond to the recirc button when the AC is on and the temperature is set at the minimum. But I now find if I crank the temperature up a couple of degrees, the recirc valve reopens. Although this allows a bit of warm air into the footwell vents it is probably the closest it will get to acting the way I wanted it to (i.e. the way all my past cars have acted!) >> I posted this three weeks ago but it never appeared on my News Server, >> although it did appear on Google Groups. But I didn't receive any [quoted text clipped - 30 lines] > accidentally once after passing a treatment works. 100 miles later I was > nodding off, until I noticed I had left it in recirc by mistake. > Mine does not change to external, no matter how long it has been > running. And it does not respond to the recirc button when the AC is on > and the temperature is set at the minimum. This begs the question - why do you have the temp set to minimum (60F)? The system can't make more coldness than it's capable of - the only way it will make the car colder faster is exactly how it's behaving - by using recirculation to recool already cooled air. I never change mine from 70F.. and the recirculation works how I would expect it to. FWIW - the "hot country" setting doesn't change recirculation mode - it changes the proportion of cold air sent to the face vents. More is sent to the face vents since that cold air blowing right on your face gives you the feeling that it's colder. If you're using manual mode to have air split between the face vents and foot vents - the "hot country" setting does absolutely nothing. > But I now find if I crank the temperature up a couple of degrees, the > recirc valve reopens. Although this allows a bit of warm air into the > footwell vents it is probably the closest it will get to acting the way > I wanted it to (i.e. the way all my past cars have acted!) And that's how it should be used. Set the temperature to where you want it to end up and LEAVE IT ALONE - the system is capable of controlling itself and achieving that temperature without meddling by the driver. Finally, someone has an answer to my question. Thank you. >> Mine does not change to external, no matter how long it has been >> running. And it does not respond to the recirc button when the AC is >> on and the temperature is set at the minimum. > FWIW - the "hot country" setting doesn't change recirculation mode - it > changes the proportion of cold air sent to the face vents. More is sent > to the face vents since that cold air blowing right on your face gives > you the feeling that it's colder. If you're using manual mode to have > air split between the face vents and foot vents - the "hot country" > setting does absolutely nothing. >> Mine does not change to external, no matter how long it has been >> running. And it does not respond to the recirc button when the AC is on [quoted text clipped - 24 lines] >it to end up and LEAVE IT ALONE - the system is capable of controlling >itself and achieving that temperature without meddling by the driver. It appears to me that one flaw in the design is that the LED on the recirc button does not indicate that it is in recirc mode during the max-cooling periods. The fan speed indicator properly indicates the current fan speed in Auto mode, why not the Recirc indicator? And why not allow me to push the recirc button, allowing me to take it out of recirc mode while leaving the fan in auto mode? The system is presuming it is more capable of meeting my a/c desires than it really is. "bjn" <elvis@example.com> wrote in message >>And that's how it should be used. Set the temperature to where you want >>it to end up and LEAVE IT ALONE - the system is capable of controlling [quoted text clipped - 5 lines] > speed > in Auto mode, why not the Recirc indicator? Indicates OK on mine, although I havn't check the current one. > And why not allow me to push the recirc button, allowing me to take it out > of recirc mode while leaving the fan in auto mode? Because it could be 40C outside, so maximum cooling is always done by recirculation*. > The system is presuming it is more capable of meeting my a/c desires than > it really is. * there are some more tricks to do with AC operation below 2.5C to prevent ice forming in the ducts. > "bjn" <elvis@example.com> wrote in message > [quoted text clipped - 15 lines] > Because it could be 40C outside, so maximum cooling is always done by > recirculation*. My question is, if I am willing to put up with a little less than maximum cooling on a 40C day to get some quiet by not using recirc, and at the same time get better air paths through the car, why can't the system accommodate me? >> The system is presuming it is more capable of meeting my a/c desires than >> it really is. > > * there are some more tricks to do with AC operation below 2.5C to prevent > ice forming in the ducts. >"bjn" <elvis@example.com> wrote in message > [quoted text clipped - 9 lines] > >Indicates OK on mine, although I havn't check the current one. The LED on my recirc button definitely does not light up when the system is in Auto and the recirc mode is enabled by the Auto mode. >> And why not allow me to push the recirc button, allowing me to take it out >> of recirc mode while leaving the fan in auto mode? > >Because it could be 40C outside, so maximum cooling is always done by >recirculation*. Overrides of automatic systems are always needed and useful. I am allowed to override the auto fan control, why not the recirc? >>> Mine does not change to external, no matter how long it has been >>> running. And it does not respond to the recirc button when the AC is on [quoted text clipped - 30 lines] > And why not allow me to push the recirc button, allowing me to take it out > of recirc mode while leaving the fan in auto mode? I agree. Manual mode should allow override of everything > The system is presuming it is more capable of meeting my a/c desires than > it really is. Again agreed. How could it possibly know the conditions in the car better than a human? And how could it know what makes the human most comfortable in those conditions. There have been plenty of comments in letters to magazine editors over the last twenty years bemoaning the loss of the simple manually controlled heater/AC system. I had a 325 as a loaner once and was delighted with the simple 'old-fashioned' heater controls. >>>> Mine does not change to external, no matter how long it has been >>>> running. And it does not respond to the recirc button when the AC is on [quoted text clipped - 42 lines] >loaner once and was delighted with the simple >'old-fashioned' heater controls. > And how could it know what >>makes the human most comfortable in those conditions. One of the things I notice is that the a/c in Auto mode overcools A LOT if the front if the dashboard (the area where the a/c controls are) has been heated by sunlight coming in throught the sunroof. The a/c sensors "think" it is much hotter in the car than it really is. > Mine does not change to external, no matter how long it has been running. > And it does not respond to the recirc button when the AC is on and the [quoted text clipped - 3 lines] > footwell vents it is probably the closest it will get to acting the way I > wanted it to (i.e. the way all my past cars have acted!) I should have a look at the manual if I were you old chap (RTFM). If you set the temperature to minimum this has the effect of calling for maximum cooling (not the ~16C it corresponds to). Maximum cooling is achieved by recirculating at a fairly high fan speed. Pressing defrost similarly over-rides various settings on the AC. So correct operation - no fault found. >> Mine does not change to external, no matter how long it has been running. >> And it does not respond to the recirc button when the AC is on and the [quoted text clipped - 12 lines] > >So correct operation - no fault found. Absolutely right - I missed the "minimum temperature" setting bit earlier. The system is working as designed. The fault is due to "IO Error" ;-) /daytripper '00 s4 6spd Possibly the only car in the world with this I/O error designed in? Certainly not in any of my previous cars over the last 25 years. But thank you for answering the non-OP. I am not talking a huge difference between interior temperature and ambient. Just a few degrees, perhaps. But it is often much more comfortable having dehumidified air coming through the vents. In fact at these small temperature differences that is more important to me than the actual cooling. >>> Mine does not change to external, no matter how long it has been running. >>> And it does not respond to the recirc button when the AC is on and the [quoted text clipped - 18 lines] > /daytripper > '00 s4 6spd >> Mine does not change to external, no matter how long it has been running. >> And it does not respond to the recirc button when the AC is on and the [quoted text clipped - 5 lines] >> > I should have a look at the manual if I were you old chap (RTFM). I have done that. > If you set the temperature to minimum this has the effect of calling for > maximum cooling (not the ~16C it corresponds to). Maximum cooling is > achieved by recirculating at a fairly high fan speed. Pressing defrost > similarly over-rides various settings on the AC. It seems perfectly normal to me to start off in the morning with the temp at minimum as I don't want any heat in the car, and then as the outside temperature rises, press the AC button for more cooling. Why would I want to increase the temperature setting at the same time if I want the car to be cool? > So correct operation - no fault found. >>> Mine does not change to external, no matter how long it has been >>> running. And it does not respond to the recirc button when the AC is on [quoted text clipped - 14 lines] > with the temp at minimum as I don't want any heat in the > car, The system is automatic - it will produce air at any temperature above 16C that you select. It won't heat it if you don't want it to. Selecting the bump stop tells it to do something different - no heating (even if well below 16C) and maximum cooling including recirculation if the AC is on. Some cars (like Jag's) have an economy setting, whereby the AC does not operate [as much] if the incoming air is near the target temperature. > and then as the outside temperature rises, press the AC > button for more cooling. Why would I want to increase the > temperature setting at the same time if I want the car to be > cool? >> >> So correct operation - no fault found. >>>> Mine does not change to external, no matter how long it has been >>>> running. And it does not respond to the recirc button when the AC is on [quoted text clipped - 21 lines] > Some cars (like Jag's) have an economy setting, whereby the AC does not > operate [as much] if the incoming air is near the target temperature. Gee. Does this mean Jag admits that total automatic control isn't perfect? I'm not alone. >> and then as the outside temperature rises, press the AC >> button for more cooling. Why would I want to increase the >> temperature setting at the same time if I want the car to be >> cool? >>> So correct operation - no fault found. |
Reply to this Message |
 Sign In
 Join
 My Latest Posts My Monitored Threads My Blog My Photo Gallery My Profile My Homepage Start New Thread Enable EMail Alerts Rate this Thread
|
©2009 Advenet LLC Privacy Policy - Terms of Use
This website includes both content owned or controlled by Advenet as well as content owned or controlled by third parties.