oil separator

A quick search o Google turned up PCV valve. I guess the oil separator is the valve which catches oil vapor on boost and recirculates it to the catch can/crankcase at idle. I suppose the system can detect the blow-by gasses recirculated into the cylinder by monitoring crankcase pressure...

Any info on what an oil separator is and what it does? Has this happened to other Malaysian A6Hs before as well? Judging from the quick response time, this may be a common issue.

After clocking 30k km, my car had a warning : Hybrid system fault!
I kept driving until I reached home, then another yellow signal ( emission control system) light up.
Although the car did not seems to have problem of running as usual, i called up Audi assist centre.
They arranged a truck to "carry" my car from my house to the service centre.
Upon checking, it was leakage of the oil separator. The engine can run as usual albeit poorer performance.
It was changed on the same day, at no cost to me.
Bravo, Audi.