[Casebrius]

How long does the Ventilate Now function stay on when invoked?

[wcr3d]

Are you talking about the parked car ventilation?
About 30 minutes.

[Qsilver7]

For every BMW I've owned that had this feature...it would run for up to 30 minutes then shut down. If your battery's power reserve starts dropping low (used to be 11.5 volts)...then it will shut off earlier.

The first two pics below are from the e38/e39/e53 era...and since BMW design architecture usually doen't change that much in regards to operational functionality...I doubt the time limit has changed...and would only be less, as mentioned, if the battery's voltage started to drop too low :

{see parked car ventilation}

[Casebrius]

Originally Posted by wcr3d

Are you talking about the parked car ventilation?
About 30 minutes.

Yes, Thanks.

[AWe90]

how do you engage the system?

[wcr3d]