Vauxhall Omega 2.5CDX T reg, external temperature error?
 
                I have a T reg Vauxhall Omega 2.5 CDX, the onboard computer keeps reporting the external temperature as -40deg or no reading at all.  I think this is now messing up the air conditioning.  As everything on the car costs an arm and a leg, can somebody point me in the right direction please.
Thanks
            
             Alistair
            
 April 2005