To replace the coolant temperature sensor on a 2002 Saturn, first ensure the engine is cool and disconnect the negative battery cable. Locate the sensor, which is typically found near the thermostat housing or on the engine block, and unplug the electrical connector. Remove the old sensor using a socket or wrench and install the new sensor, making sure to torque it to the manufacturer's specifications. Finally, reconnect the electrical connector and the battery cable, and check for leaks after refilling the coolant if necessary.
Refer to the link below
Replace your Engine Coolant Temperature Sensor. Visit Saturnfans.com for help in diagnosis
The sensor is threaded into the coolant passage in the back of the cylinder head.
Replace the engine coolant temperature sensor. Your car has two, replace the one with the 2 wire connector
Engine coolant temperature switch/sensor
Faulty coolant temp sensor can cause the vehicle to run poorly, if run at all. If you are leaning toward replacing the sensor you will be happy to know the sensor is relatively cheap, around $12, and simple to replace. Please visit my Bio for a link to my saturn help site for image of where the coolant temperature sensor is located.
Replace your Engine Coolant Temperature Sensor. Your car has two, replace the one with the two wire connector
under the backseat and you just pull it out and put a new one right back in
on the right side of the engine
Engine Coolant Temperature Sensor.
To replace the coolant sensor on a 2004 Saturn Ion, first, ensure the engine is cool and disconnect the negative battery terminal to avoid electrical issues. Locate the coolant temperature sensor, which is typically found near the thermostat housing on the engine. Remove the electrical connector and unscrew the old sensor using a socket wrench. Install the new sensor, reconnect the electrical connector, and reattach the battery terminal, ensuring to refill any lost coolant if necessary.
Start by replacing the Engine Coolant Temperature Sensor