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-   -   no face vent heat on AUTO (https://xoutpost.com/bmw-sav-forums/x5-e53-forum/109828-no-face-vent-heat-auto.html)

Russianblue 02-16-2019 10:54 AM

no face vent heat on AUTO
for some reason I cannot get air to blow through my face level air vents when my heater is on the AUTO setting. not consistently anyway. if I press the face vent button, the warm air flows immediately. if I press auto, it doesn't.

it doesn't matter if the cold hot wheel is toward hot or cold. if it's on auto, I can roll it all the way up or down....but nothing happens.

but wait...on a completely random basis, but sometimes never, after I drive around for an unspecified time with the IHKA on auto, all a sudden out of nowhere the vent will open and air will start flowing from the face vents. it's as if the vent servo finally just activates itself. but it hardly does this anymore.

any ideas?

cn90 02-16-2019 11:37 AM

What does the owners manual say?

Russianblue 02-16-2019 12:32 PM

if that's a not-so-subtle suggestion to RTFM, while I appreciate all the time you took to come up with it, there is something not right when compared to 2005 X5 sitting in the driveway right next to this 2003. The vent action on AUTO behaves entirely differently. there is definitely air coming from the face vents with the heat on auto. it's not full force, but it is certainly more than in my 2003. and the cool/hot dial works very well. I use it all the time.

can you direct me to a page of the manual which addresses this?

Qsilver7 02-16-2019 12:45 PM

Since the AUTO setting is going to be using the tempt thermistor that is located just within the "vent" on the left side of the IHKA control panel to help regulate things...have you checked this vent for collection of dust?

There could be a small possibility that the older X5 could have a larger collection of dust that may be affecting how this thermistor is reacting...thus when in AUTO mode...could be regulating air distribution differently.

Also, we can't see how the IHKA is set...do you also have the fan speed set on AUTO as well? If you didn't know...fan speed can be AUTO or manual...when it is in AUTO mode...the word "auto" appears in the fan speed display. When you manually select a fan speed...the word "auto" disappears from the fan speed display and the HVAC blower is in manual mode.

BTW...I'm just throwing spaghetti noodles at the wall to see what may stick...so don't bite my head off if this is something you've already considered. :D

Another thought that came to mind that could have the same type of IHKA set-up react differently is the position of the dash vents...especially the one ABOVE the IHKA control panel.

There is a known issue where the footwell can sporadically blow heated air (much to the chagrin of the driver) when cooler air flows downward from the center dash vent into the IHKA control panel (i.e...the same little vent mentioned at the beginning of my reply). If the vent in tthe 2005 is angled differently than the 2003...even though the IHKA control panel is set the same...the reaction/function of the systems could be different depending on how the IHKA control panel is interpreting the data that it is collecting from the air temp in the cabin being sucked in across that thermistor.

cn90 02-16-2019 12:59 PM

In the link below, Page 109 talked about "Auto":


I am still trying to figure out when you hit "Auto", does the HVAC unit "remembers" what you LAST programmed it in terms of which of the following?

- Blower Speed
- AC (On or Off)
- And Vents settings

I forgot how to "program AUTO".

Russianblue 02-16-2019 03:07 PM

This is all good information and I believe it will require a thorough going over each part of the system. Great place to start!

To answer your questions, I am definitely referring to when I click the AUTO button and AUTO appears on the display. When I click the face vent button AUTO disappears from the display. That's when the issue occurs.

I think the first thing to do is probably to check for any hardware/parts problems issues. In this case, it sounds like I need to verify that the Aux water pump and interior temp sensor are up to snuff like you mentioned, among other things. Is there a simple way to test the heater valve itself or the external temp sensor. those are also part of the input system.

I checked BMW Scanner and I am in fact getting one code for the AUC. I remember trying to open that thing and clean it at some point and simply could NOT get it apart. I suppose I could just break it apart and duct tape it back until I got a new one if that's necessary.

let me try blowing out the interior sensor dust and testing the aux pump and i'll take another crack and the AUC and report back.

wpoll 02-16-2019 03:17 PM

Opening the IHKA requires a few small pieces of cardboard...

Repairing buzzing noise from HVAC


mr_robot 02-16-2019 04:47 PM

I have to press the AUTO button twice so the AUTO text comes up on the display.

So from what I can see when I first press it is AUTO ventilation. Then when I press it again and AUTO text is displayed then everything is automatic.

Then with the AUTO displayed if I press any of the ventilation buttons the AUTO text stays displayed while the ventilation button I selected is on and fan speed remains automatic.

Either way I don't like to use the AUTO feature as it will blast the fan to reach the set tempature as quickly as possible and the fan noise is annoying.

So I just wait till the coolant is up to operating temp and set fan speed to 3 manually.

Russianblue 02-17-2019 11:43 AM

well, turns out I have multiple issues to take care of before continuing to assess. first off, the aux water pump was dead. I think it's probably been dead for years and I always thought the X just had a crappy heater until I got my 2005, which has a GREAT heater. I'd suspected this a while back on the 03 so I had a replacement at the ready which I installed in about 15 min.

2nd, I turned on the secret menu and watched the coolant temp while driving. it will not go past 84c...which may explain why there are some traces of soot under the tail pipes. in my 2005, the fully warmed engine is between 90-93C almost always.

so that means the 6 year old T-stat on the 2003 is probably bad. i'll change that this week.

after replacing the aux pump, the heater behaved a tad differently on the Auto setting. I still need to spend some more time this week assessing it but my first hunch is that I could have a partially stuck heater valve. there's a definite change in the temp of the air coming from the vents when at a stoplight compared to driving. I have to eliminate all these issues though before I can get an accurate assessment of the IHKA situation because all of those parts affect the way the heater behaves in various situations.

Qsilver7 02-17-2019 01:51 PM

Thanks for the update...does sound like you have some issues you need to suss out. Good luck. :thumbup:

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