2011 e70 X5 Transfer case VTG calibration problem

[ChristyMcL]

Hello,

Have the 4x4! and DSC error Light.

Scanned with ista and have the following errors:

005227 Transfer box VTG calibration faulty

5F3A Dsc Transfer case malfunction.

Currently only operating in rwd due to this error.

The actuator is the newer model on the ATC 450 transfer case so the plastic worm gear issue doesn't apply.

I have went through the process of the Transfer case repair/replacement and read the 3 digit classification code then recoded this value and then the initialisation process but When I get to the VTG Calibration, I get a 'No Valid calibration value stored in the VTG control unit'.

I have removed the VTG unit and can confirm that the actuator turns when the vehicle is started.

If I turn the part that the actuator is responsible for turning manually on the transfer case while the vehicle is in gear the xdrive engages the front wheels as it should.
Am I right to think this rules out any internal problems the transfer case itself ?

Anyone else ever had this problem where the VTG wouldn't calibrate? And does this Point towards faulty actuator/VTG