TD5 Auto Box - wxyz

Have any of you guy's had the following happen with your Auto Box.With the selector in Drive and engine cold or hot it seems to hold onto first gear far to long.I have to push selector to 3rd position to try to get it to change to second and onwards.Could this possibly be anything to do with the wxyz switch,although this i was informed was changed three years ago.Can it get dirty and give false info to the ecu.

Thanks in advance

WXYZ switch is not likely to be your problem,if it gives an invalid signal to the autobox ECU it will go into limp home mode and the S and M lamps will flash.Hanging on to first gear is a common ZF 4spd problem.Have a look at Ashcroft Transmission's website in their FAQ section.

Mine was same and cured with a Gearbox Oil and FILTER change

Thanks to both of you for your assistance,will try the cheaper option first of course,and keep fingers crossed it cures.