Hi can anyone help. I have a freelander 2004 TD4 the parking sensors have stopped working and the switch on dash flashes is this an easy fix or is gonna cost an arm and leg

The parking sensors do seem to have a mind of their own. Mine worked fine then stopped for a continual beeeeeeeeep whenever I put it in reverse but now they seem to be working fine. I found turning them off for a while helped. Not the most technical I know but worked for me