Turbo Control Valve and its Correct Hosing Routing

Let’s Talk Turbo Control Valve

TCV Vacuum Hose Routing De-Confusement

I have searched for TCV diagram for my 95 Volvo 850 T5 but getting confused with these 2 diagrams. When i look at both of my cars the wastegate actuator has been marked yellow and also the vacumm hose has a yellow sticker on it. That makes sense if i follow the frist diagram, yellow line will go to the top port of TCV but! the second diagram showing the wastegate vacumm hose must run to the buttom port of TCV. So, this making me confused which diagram should i follow?

jblackburn » I think they kept it the same between the years – yellow should go to the wastegate, red to the turbo, and blue to the fresh air hose.

The turbo control valve on my S70 is shaped a little different, but is set up in exactly the same way.

ojdorson » The two diagrams say the very same thing. The problem occurs in the second image where the “artist” made color choices that don’t match the markings on the BCS. Here is the image properly colored.

Of course, the BCS pictured is “upside down” compared to the one in your hand in your picture.

TCV diagrams confusion – explanation

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Last Updated on February 10, 2026