That's not for overheating, it's for the engine coolant-temperature sensor being bad or maybe unplugged. The ECU can't tell the difference between a bad sensor vs. unplugged vs. a broken wire anywhere in that circuit.

On my '95 that sensor is located sorta below the distributor, in the head. There's a single-wire sensor (for the dashboard gauge) next to the 2-wire sensor. It's the 2-wire sensor that you want. Check to make sure it's plugged in & the wires aren't broken.