Hi this happened to me car. I had engine hesitation, high idle, stalling, temp gauge didn't work and the fan didn't turn on. I did a visual inspection and saw it had a crack in it. I replaced it and everything went away.
The sensor is threaded into the coolant passage in the back of the cylinder head.
Engine coolant temperature switch/sensor
Engine Coolant Temperature Sensor.
on the right side of the engine
Start by replacing the Engine Coolant Temperature Sensor
The guage on the dash uses the ONE wire sensor... This is located in the block near the drivers side. Eric First check to see if you have coolant in the radiator. If there is no coolant you will not get any reading from the temperature sensor. If there is coolant then change the temperature sensor.
Refer to the link below
Where is the coolant temperature sensor on a 2001 ford focus?" Where is the coolant temperature sensor on a 2001 ford focus Where is the coolant temperature sensor on a 2002 ford focus
engine coolant temperature sensor is faulty. engine coolant temperature sensor is faulty. engine coolant temperature sensor is faulty. engine coolant temperature sensor is faulty. engine coolant temperature sensor is faulty.
The engine coolant temperature sensor is usually on the front of the engine. The coolant temperature sensor will be in the vicinity of the thermostat housing.
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. Visit Saturnfans.com for help in diagnosis