Sorry for got to emphasise the point, low air pressure warning light on and buzzing . You can still take the handbrake off and it will travel forward when there is no reading of air in the tank but takes 4 mins to fill. Obviously I have only moved a few feet forward and there is a pedal to stop it. I was under the impression that the hand brake should not release when the air is low and the vehicle can’t be moved. I did consider it might be a faulty reading on the low air side, but the seat inflates to normal and the suspension adjusts its self to ride position, indicating air is required to me.