fault following cambelt change

[T5TIM]

just had cambelt done (full kit) and within a few miles had engine management light on and code 644A "Camshaft control.. faulty position permanent".

Ive had the timing marks double checked but as mine is a VVT model, is there a specific way the belt should be done?

Any idea's?

TIA

[C70 GTT5]

may just be a faulty sensor mate you would be able to tell if the belt was out a tooth as you'd be getting flat spots, power loss etc