So ECT (Engine Coolant Temp) is a code.
The quick and dirty deal is to plug in a resistor across the connector terminals so you can rule that out. The computer does monitor this so it can see how quickly it comes up to temp. There are codes for this, but at least you can plug in a 90 degree resistance and see if it's still super fat.
From THIS PAGE it looks like a 5k ohm resistor will do it. Clear the codes after checking.
If the connector is disconnected, it will be no retun and 'see' very cold and force it rich. Check those wires!