Unidentified part

Hello, what color is the wire? And what sub-model is this car, DX, EX, LX, and is this a Canadian model? Its bolted to the block near the coolant sensor it might be a thermal switch. Being that its so close to the thermostat.
theres another one on the radiator, usually at the bottom.

https://www.2carpros.com/articles/how-a-coolant-temperature-sensor-works

It is an ex model, it’s a black wire.

Is the wire broken or is the check engine light on? It's most likely just one of the thermal switches for the radiator fan control module. The aftermarket wiring diagrams are not always the same exact colors. But a 1 wire switch running right next to the thermostat is going to be a heat related on/off switch. Or its the Ground for one of the thermal switches. The Engine Coolant Temp Switch B grounds at the left rear of the engine which is right where your hand is. Your car has a transverse engine, meaning its sideways in the engine compartment. Your main drive belt is on the right side when facing the car, correct? (driver side) that is technically the front of the engine.