I have an A8 4.2 TDI 2011 that has developed the following problem. The electric radiator fan ( one on left when facing car) runs at full speed with the engine off when it senses voltage. So it will be triggered when opening with remote, opening of boot ,opening of door etc. it will continue for about 30 seconds when alarm is set and will then switch off. It also runs at full speed when engine is running.

The car is out of warrantee so I am cautious of approaching Audi main dealers, has anyone come across this as this cannot be an isolated case?

I have access to a good auto electrician & have basic mechanical knowledge but no access to new shape a8 diagnostics.

 

You need one of these: Ross-Tech Store: VCDS License with HEX-USB+CAN (All VAG)
Distributor list, since I think you are in the UK Ross-Tech: Distributor List

It sounds like a bad controller on the fan, I have heard of this before.
Hopefully it's not caused by a leak into the wiring harness.
Have you had all the recalls / campaigns done ?

 

Thanks for your reply. All recalls upto date, no water ingress in loom etc. I have contacted the biggest Audi dealership in Europe who are denying any knowledge of previous cases like this. However, after studying many discussions it appears this is quite common in other models. Take a look at the following that is exactly the same symptoms just cannot tell if it is the same or previous model A8 to mine.

4.2TDI radiator fan running constantly - A8 Parts Forum

 

And here on a 2011 3.0 TDI Second Fan Keeps Running - AudiWorld Forums

 

Thanks for that.