kaldoc

I have had my 535d for 2000 miles, what a superb car (I changed from a Lexus Rx 300). My air con worked fine (ie set to a desired temperature - then it worked in the background and I wasnt aware of it for most of the time). The windscreen was then hit by a stone and had to be replaced, since then, when the air con is set to auto instead of it working fairly silently, there are sudden prolonged noisey blasts of air - mainly from the windscreen vents - using the i-drive I can see that the windscreen fan is set to maximum during these blasts of air - if I change the setting auto mode is disengaged. Any thoughts ? Is the change of windscreen a coincidence or could some sensors have been damaged.


535d Saloon - Media Package, Luxury Package, Visibility Package, Tracker - Retrieve, Sun Protection glazing, Heated rear seats, Through-loading system including ski-bag, Steering wheel heating

browellm

The mist sensor is in the cluster of sensors where the rear view mirror is attached to the windscreen, so there could well be a malfunction there.

Merv the Derv

Have I missed something here but what mist sensor? I didn't realise there was one. Does it automatically switch to the intense windscreen mode if the screen mists up. If it should then mines not working.

Boxsterfeet

Not that I'm aware of. To be honest the a/c is the only thing that I think could have been done better on the car. I miss the old 'internal temperature' settings in digital so that you can tell when the car is pushing the temperature up or down. In my Porsche if I set the temperature anywhere above 22 degrees it was too hot - in the BMW it has to be set to >26 degrees to feel any real warmth.

kaldoc

Problem solved, there is a mist sensor (also known as a de fogging sensor) in the rear view mirrow cluster . It compares temperature and humidity inside the car to that outside, decides if there is a chance of the front window misting and redirects air accordingly. It is fragile and should be replaced if the windscreen is relaced. If you use Autoglass - ask them to ring their technical division, before replacing the windscreen, so they have a new sensor ready, its likely your local branch havent a clue (mine didnt). New sensor on order!

EBMCS03

Wow cool. Look how smart the board is! Something new to learn everyday!

FJPM

If you select on the ac dash panel the auto setting: it will be automatic: it means that you cannot regulated the diffusion even whith the I-Drive.

The only thing you can regulate is through the I-drive to set the auto mode in 3 psoitions ranging ? weak to strong. It influences the airflow speed.

But maybe you sensor as been damaged?

browellm

Merv

There is an a/c TIS document on here somewhere - very informative.

The advanced a/c is massively clever, it has about 6 stages of things it does in a particular order, if it senses condensation forming on the front screen.