HOW CAN I FIX MY VAUX CORSA OUTSIDE TEMP SENSOR?

I HAVE A 2002 VAUXHALL CORSA WHICH IS SHOWING THREE DOTS ON THE OUTSIDE TEMPERATURE UNIT. I HAVE REPLACED THE OUTSIDE SENSOR AND THE DASHBOARD DISPLAY WITH KNOWN GOOD ITEMS. I HAVE CHECKED THE WIRING AND THE CONNECTIONS FOR CONTINUITY. AND MEASURED AGAINST ANOTHER CAR. EVERYTHING APPEARS TO BE OK BUT THE THREE DOTS REMAIN. I WONDER IF THESE GO THROUGH THE ECU