audi a4 b8 not boosting

[malsl3]

Hi. would be great if someone could help. i have a 2009 a4 avant 2.0 tdi. For some reason it dont boost at all. I checked the vacuum pipes the breather pipe to the airbox seems to work fine but the one that goes to the wastegate/actuator there is no vacuum at all. You reckon this is a fault with the boost solenoid or something else. I have engine light on and glow plug light. fault showed something about boost solenoid and also glow plug bank one. whatever these mean.
thank you