As the position switch is a hall sensor the sliding surfaces are magnetic and just the debris over the years can disable it. So just removing and cleaning it might cure it. But of course when the mechatronics is on the table you should check the components and be prepared to renew things if needed. Easier done if you have a possibility to have the vehicle standing for a while.

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E39 530dA -02 M-Sport Messing metallic
E53 X5 3.0dA -06 Sport Stratus grey
E70 X5 40d -12 M-Sport Space grey