This post starts from my problem with Passat 2.0 which read out P2563 error code by ELM327 Bluetooth, then followed are solution. 

Car model and year: 

Passat 2.0 TDI Sport 5dr Estate (170PS) 3C5 M6F CBBB

-ELM327 Bluetooth plug (£6 from obd2express.co.uk) via ODB car doctor app on a Samsung Galaxy S5

I bought from 

http://www.obd2express.co.uk/wholesale/elm327-bluetooth-software-obd2-can-bus-scanner-tool.html  

-Genuine VW turbo actuator

Symptoms and error code read out by ELM327 Bluetooth:

meta-info header:Error Codes

file version:1

type:5

time:1402173015621

name:Trouble Codes

codes:P2563,

codes_p:P2563,

codes_raw:43012563

codes_p_raw:47012563

*****

Error Codes

P2563

Turbocharger Boost Control Position Sensor Circuit Range/Performance

Vehicle speed (Speed) 0 mi/h

PIDs supported [21 - 40] 00100000000000000000000000000000

Intake air temperature (IAT) 68 °F

Engine coolant temperature (ECT) 71 °F

Fuel Rail Pressure (diesel, or gasoline direct inject) (FRP2) 0.9871668311944719 Atm

MAF air flow rate (MAF) 8.69 g/s

Calculated engine load value (EngineLoad) 26.66 %

Engine RPM (RPM) 783 rpm

Throttle position (TP) 83.92 %

Intake manifold absolute pressure (MAP) 0.9772951628825272 Atm

P2563

Turbocharger Boost Control Position Sensor Circuit Range/Performance

Buy a genuine VW turbo actuator fitted for £220 by a local independent. All sorted.