Thanks for your help. Good to know it isn't a fault.
What do you mean by locked - genuinely locked in place as in removing ignition key or stiff to move? If engine cuts due to Start/Stop working then steering becomes very stiff as is no assistance but engine will start again if you move wheel against the resistance.
Well mine doesn't lock in sense that withdrawing the key ot and turning the wheel slightly until the pin engages. That is when the steering is locked, in my opinion anyway.Can anyone offer a good reason, sounds like a design fault to me ?