VXOC Astra-J/GTC

Hello All,

Strange fault on my Astra, the outside temperature gauge fluctuates wildly goes from -2 to +17 in a short time then back to say +4 before moving again, the heat coming out of the vents is almost uncontrollable too no matter the setting on either side heater control

The external sensor was replaced last year following a front end rebuild after a shunt 

Any ideas please folks ?

Maybe a you're HVAC needs a re-flash, or it could be something more to do with the crash.