Make sure you replaced the sensor with the two wire connector. Make sure the connector to the sensor is corrosion free. Replace it if it is
The sensor is threaded into the coolant passage in the back of the cylinder head.
In the expansion tank.
he radiator
It should be on the right hand side.
Engine coolant temperature switch/sensor
at the bottom of the coolant reservoir tank.
The computer is not seeing a voltage drop across the coolant sensor. You could have a bad sensor, broken wiring, or a bad computer.
An engine coolant temperature sensor will usually need to be replaced when it is drawing too much or too little voltage. The sensor may also have a bad ground connection.
on the right side of the engine
Engine Coolant Temperature Sensor.
Fill your coolant to the level that it should be at. If it still comes on when the coolant is at its proper area, then it is an improper sensor. You will need to have it replaced immediately to reset the sensor.
probably just replace the coolant sensor