A/C auto switch not working right - Geez Tech?

[JeffFL745Li]

My passenger-side auto switch for the A/C will turn itself off every once in a while.

On the I-drive screen at the bottom there is the left and right fan displays that always say 'Auto'. What will happen is as I am driving the passenger one will switch to the white bar that controls fan speed (the green light on the Auto switch actually stays on) and the fan stays on whatever speed it happened to be on when it switched. I have to press the Auto button again and it will resume working properly - sometimes for 5 minutes, sometimes for a month.

I can't reproduce the problem and it is not caused by bumps or anything. It happens whether it is heating or cooling the car.

I've had the dealer look at it twice and they said they couldn't reproduce it and everything tested out fine. Ironically, both times they looked at it, it worked right (stayed on Auto) for a few months then started acting up again.

If anybody has had a similar problem and figured out how to fix it, I would appreciate it.

[GeezTech]

....a false fan speed input from the knob as this is what will take it out of "auto".
I have seen other reports here of the display flashing at times and the fix there was a new A/C panel which may be the case for your car. The problem the dealer has is that the panel may not be setting a fault snce it "thinks" the fan speed input is coming from the knob being turned by someone in the car, even though it actually isn't.
If they take your word for it then they may replace the panel and go from there. I'm sure they have done software changes for other reasons and this problem may still persist, right?

[JeffFL745Li]

Yes, both times I took it in they did a recall and updated software and I thought it was fixed...only to return months later.

[scottw]

[scottw57]

Suwanee, Georgia (Atlanta)
2004 745li
Sterling Gray Metallic
Black/Natural Brown Leather
Premium Sound with Sirius Satellite Radio
PDC, Conv. pkg, Elec.sunshades, 19" custom Bereyn wheels