Hi, i own a 2005 a3 2.0tdi s-line with navigation, anyway the outside temperature on the display shows wrong readings. When outside temp is 1 celsius i get - 9 on the display. Been to the service, they disconnectted the gauge and then it worked fine, after one night the display is showing wrong temp again. Any ideas or solutions what could be wrong? How do i disconnect the gauge myself? Tnx