E60 530D Main fan running at high rpm

04 530D 95k miles (No other issues)

I started my car today engine started no problem, 2 seconds later the fan kicked in at high RPMs! It's so loud it drowns out the sound of the engine even with the bonnet open!.

I left the car idle for about 5 minutes to see if the fan would stop but no luck, checked all the fluids etc & the engine and oil temps were normal so I went for a 10 minute drive. Cool wet day around 10c/50f

The car ran normally without any warning icons on the dash/iDrive.
Got back home turned off the engine let it cool for a bit started the engine again and of course the fan kicked in running at a crazy speed, the damn thing sounds like a huge vacuum
First thing that came to mind was the thermostat is fried so I decided to check around the net to see what I could find and yep it sounds like either the temp sensor or something linked to the thermostat.

That was all fine and dandy until I started the car again same issue with the fan running constant and at high speed but then I turned off the engine and heard this weird (what I can only describe as) an electronic beeping or an alarm that had been hit with a hammer this beeping stopped after about 30 seconds but beeped twice when I unlocked the car with the remote!

So is it the thermo making the fan kick in at a constant high RPM?
And what the hell is that electronic beeping sound?

Anyone help a fellow bimmer nut out before I get hijacked by a main dealer ?

Does it stay running at high speed after shutdown? Beeping hit with a hammer.
For that I can say you accidentally activated the alarm? Hold down the trunk release button for five second and see if that's the same sound? Two beeps after unlocking seems normal indicating doors unlocked.

http://www.bmwland.co.uk/forums/view...29799&start=60

Hi boramkiv
The fan stops when I turn off the engine it only runs when the engine is on.
The electronic beeping starts when I turn off the engine, I've tried it a few time but the noise keeps beeping. I haven't accidentally activated the alarm.
The beeps after unlocking sound completely different, the engine bay beep is more like the the electricity discharge that normally happens when the engine is switched off only a lot louder.

Thanks for the link

It turned out to be a faulty DDE control unit
€1,600 fitted and reprogrammed, with updating the SW it's a possibility that other components may fail, relays or sensors etc