Hi guys,
My engine light came on my A6 2018 on Saturday with no clear reason why, then Sunday the car was cold and not been driven for hours the radiator fan came on full blast and did say for a short while.
Monday the car would not start has I think the fans may have drained the battery.
My friend who is a mechanic had a look and noticed water ingress from near the plenum to onto the harness in the engine bay that was then tracking to the engine ECU.
ECU connections are blue and corroding, it now has to go to Audi to have the necessary investigation and works carried out.

Has anyone heard of this issue before?

Would be interested to know.
 

Nathan

That's shocking on a car less than 5 years old. I'm assuming it's a diesel. And from this my hunch would be that the car ECU thinks the cars doing a regen of the dpf. If you turn a car off during a regen the fans can stay on a little while after. 

Has your mechanic done a diagnostic check to see if any fault codes flag up at all? 

Nope, it’s a petrol. 
 

Yeah the diagnostics pulled up issues with coolant temp which would make sense with the fan coming on. 

36 minutes ago, Nate_T said:

Nope, it’s a petrol. 
 

Yeah the diagnostics pulled up issues with coolant temp which would make sense with the fan coming on. 

I guess that's make sense too.