Is it possible to reset the Temperature Sensor?

[Phil303]

The sensor the gives the dash reading of the outside temp was unplugged to fit a new wiper motor.

Now the dash shows an outside temp of anything from -25 to -5. I've unplugged and replugged it in with no success. Is it possible to reset it somehow?

To be clear; the sensor I'm referring to is a white plastic prong about 5cm long that is fixed to the front of the scuttle, near the pollen filter towards the back-middle of the engine bay.

Thanks.