A4 cab 2003 temp gauge and traction control not working ?

On my Audi A4 cab 2003 I've had it for 3 years now and ever since I've had it the temp gauge and traction control have never worked as the traction light is always on ,on the dash and no matter if u press the button it changes nothing but now and again I'll notice the light go off and my temp gauge workin only for a limited time some times 10 minutes other times a couple of days and the cars seems to run smoother ? What could cause this would it be a Ecu problem ?

But why do they both come on together when the traction control light goes off you can manually turn it off and on and the the temp gauge sits perfectly in the middle ? Surely it's something connected ?