This article describes what the TCV does.http://www.wothrline.com/Cars_engine/HW ... _valve.htm
Note that high performance TCV gimmicks can ruin your cars engine.
I installed an ARD unit in mine looking added performance like their selective testimonials only to fine it ran worst, it ran smoother and faster with my original. When it arrived it also came with a disclaimer on how it can ruin the engine that was not on their site. Of course they don't take it back and shipping cost almost as much as the part.
( so called high performance that did nothing, worst yet can break your engine)
I wished I read this article before buying this junk.
The article states:
"Later I have experienced that so called High Performance TCV's are becoming more common.
This is a unnecessary component that will cost money without adding anything to your car.
A TCV that is not behaving as the stock Volvo part may damage your engine.
Problems with boost control can be related to high performance TCV!"
As for routing:http://www.vivaperformance.com/genuine- ... valve-tcv/
Red=Turbo Compressor nipple
Blue=Fresh Air hose
Yellow=Turbo Waste-gate nipple
Green=(does not attach to TCV) Intake Manifold to CBV only