Good afternoon all, I apologise if there is an answer already out there somewhere for this problem but I can't find it

I have a 2.0 turbo Vectra on a 54 plate which has been feeling under powered lately and last week the spanner light came on while driving. The code that came up with the flash test was P0034. After a little Google session I know this is Turbocharger Bypass Valve Control Circuit Low but what does that mean in layman's terms.

I'm generally up for most jobs and don't mind getting my hands dirty but could do with a few pointers if you don't mind chaps. Anything to keep it away from the fleecing dealer prices lol