The turbo has been overheating, causing the wastegate flap seat to become loose and move.
The car's computer (DME) is trying to "learn" the closed position of the wastegate valve. The measured closed position is outside the acceptable tolerance, indicating it is not sealing or moving properly. Common Causes: 123432
The actuator motor itself is failing.
Faults can sometimes trigger after a complete disconnection of the battery. The turbo has been overheating, causing the wastegate