engine management light / engine fault workshop

[rallyroy69]

hi there peeps, im no mechanic lol and im new to this site and have no other option other than to try and find other ppl with the same prolem and have solved this or someone who can guide me in the right direction, I have a 2009 gt tdi 170, ive only had the car for about 6 months I was driving along the M6 at about 60 or 70mph when all of a sudden no boost, at first the glow plug light was flashing and came up on dash saying engine fault work shop. so I took it to a mechanic who plugged it up to his computer diog thing and came up with " boost pressure regulation control
range not reached P0299"
he mentioned he wasn't quite sure the resolution to the matter so he asked another mechanic who immediately said he needs turbo repair kit. but possibly new turbo which ive herd is a right sting!!! then checking on google etc im seeing could be this could be that, is there anyone on here who could help with just simple steps of
what it could be
common problems or fixes
rather than me just going off mechanic 1's advice , lol I would really appreciate it if anyone has had this problem and knows info that could help me, kind regards from roy.