Need help with p0299 and limp mode :(

[Viper143]

Hi everyone

A week ago i took my car ( 2015 2.0 TDI CNHA engine) to a shop for standard service ( changing oil and all the filters) Right after this service when i was driving, at first everything was fine but i was not using the throttle much because MMI was saying “please reduce engine oil” so i thought maybe it’s overfilled maybe sensor problem to give it sometime i shouldn’t go hard on the engine, after 15-20 mins when i needed some speed car switched to limp mode above 2000 or 2500 rpm,i pulled over restarted the car. At first it was fine but when i increased the throttle car switchs back to limp mode again and again...
I did take the car to the shop back and they’ve only found P0299 code.. nothing else… they did remove and check the turbo and it’s fine any ideas what it could be…? I’m loving the car but when i googled this situation I’ve found so many cases with the same problem they’ve been dealing for months.. It’s frustrating and scary that i’d have the same thing… :(
Please let me know if you have any experience or idea about this situation
Thanks in advance

[Crasher]

P0299 is under boost and is usually caused by a vacuum leak in the control system so they should start by applying a vacuum to the vacuum pump connection and see if the system holds a vacuum, if not, investigate the leak.

Connection diagram - vacuum system

1 - Vacuum line
2 - Non-return valve. Note installation position
3 - Cylinder head cover with vacuum reservoir
4 - Position sender for charge pressure positioner -G581- on turbocharger
5 - Control pipe for vacuum from charge pressure control solenoid valve -N75- to vacuum unit on turbocharger
6 - Charge pressure control solenoid valve -N75-
7 - To brake servo
8 - Non-return valve, note installation position
9 - Vent line
10 - To air cleaner housing
11 - To vacuum pump in oil pump

https://live.staticflickr.com/65535/52714420716_8a44fa44a8_o.jpg (https://flic.kr/p/2ojcbJG)

[mickeybo]

This to me is a typical case of sticking vanes within the turbo when your turbo was removed was this not sticking vanes not checked out. The vacuum on this needs/has to be checked out with a vac gauge & readings has to be approx 26/27 in/hg check these & post back