were is the temperature sensor located at on a 2004 chevy aveo

That is the thermostat, NOT the temperature sensor. And that controls the flow of the anti-freeze and coolant in your vehicle. That has to be replaced by a professional, such as your car dealer. So I would take that car to the nearest car dealership ASAP to get that replaced. It will cost you between $200-$500 depending on if the thermostat housing has been split or not. Do not replace that yourself, because that is a very tricky job to do and requires professionals to do that.