Radiator Cooling Fans Run Constantly

That “sensor” is actually switch, because it only has two possible states. If temperature is bellow specific resistance is high (but not too high) car will check it and know that sensor is connected (but not turning fans on). If temperature is above specific resistance is low (basically zero) car will know it and know that sensor is connected (and turning fans on).

Only way to car to give fault code from this would be that they would build in logic that calculates estimated inverter coolant temperature based on at least inverter and MG temperatures. If that calculation gives out low temperature but switch reports high temperature or other way around then fault code would set. Of course it would need margin. But they probably just didn’t write this code.