I am not current by any means with many makes of contemporary cars, but those I have had anything to do with used the coolant temperature sensor as the input to

I am not current by any means with many makes of contemporary cars, but those I have had anything to do with used the coolant temperature sensor as the input to the fuel adjustment. I'm not saying that's universal, but it certainly is common, and makes a lot of sense if you're looking for a reading on the engine operating temperature, since that's what the coolant regulates.