Could be one of two parts or both, the turbo "actuator" it's self or the " control sensor" sorry I don't know the part number but just do a Google you find something. Also before you splash out try to see if the vacum hose are ok.
Also check all wires to control sensor,
The actuator controls the turbo vanes in the turbo housing body this regulates the boost to your intake manifold, the control sensor controls the vacum to the actuator.
THanks. Will check wires first. Can I run 'output test' with VAGcom (gas engine expert, newbie on TDI) to check if the actuator moves?
Also read somewhere that there are 2 different type actuators used: one 'pushes' and the 'pulls'?
Yeah probably but the turbo actuator will be hard to see because of its location (lower back of engine) so your have to be underneath with a torch.
I'm almost certain your actuator pulls, check vac pipes and wires first will be the easiest then if all ok you know it's gonna be the sensor or actuator so you can either remove actuator and test for leaks or just buy the pair.
Turbocharger Boost Control Position Sensor (G581) - Signal too Low
Malfunction Indicator Lamp (MIL)(K83) active.
Turbocharger Vane Position Sensor (G500) faulty.
Check/Replace Wiring/Connector(s) from/to Turbocharger Vane Position Sensor (G500).
Check Turbocharger Vane Position Sensor (G500).
When found in VW 2.0L PD TDI with engine codes BRM and BEW see Measuring Block 043.2 for Turbocharger Vane Position Sensor (G500) readings.
Key On, Engine Off (KOEO) Measuring Value Blocks (MVB) 043.2 should be 0%.
Key On, Engine Run (KOER) Measuring Value Blocks (MVB) should be 100%.
VW TDI forum, Audi, Porsche, and Chevy Cruze Diesel forum
A forum community dedicated to Audi, Volkswagen, Porsche, and all turbo diesel owners and enthusiasts. Come join the discussion about performance, modifications, troubleshooting, TDI, maintenance, and more!