Recently purchased an E53. Have questions!

[Qsilver7]

Originally Posted by SineDeviance

I have noticed a buzzing sound that seems like it's coming from the climate control panel after I shut off the car (and sometimes when I get back in the following day.) It kinda sounds like a cabin fan on the lowest setting. I just assumed it was the timed vent fan. My MID has a ton of missing pixels so I currently can't check/change the settings on that module.

There's a little fan inside the IHKA control panel that is included in the 16 minute consumer cut-off feature.

This little fan turns on as soon as a wake-up call is made to the P-bus. It begins to draw cabin air in across a thermistor which facilitates maintaining the temperatue set on the IHKA. This fan continues to run up to 16 minutes (if no calls are made on the P-bus) in case you come back to the vehicle for more driving.

So when you unlocked the vehicle with remote key or lifted the door handle...the little fan turns on...and if you're sitting in the car...it will stay on after shutting the engine off for 16 minutes. If no calls are made on the P-bus...then the little fan will shut off. If you activate anything on the P-bus...then the fan will continue to run.