The Coolant Temperature Sensor is used to measure the temperature of the engine coolant. The readings from this sensor are then fed back to the engine control unit (ECU). This data from the sensor is then used to adjust the fuel injection and ignition timing. On some vehicles the sensor may be used to switch on the electronic cooling fans as well. The data may also be used to provide readings for a coolant temperature gauge on the dash.
The ambient air temperature sensor is used to measure the temperature of the air outside the vehicle. It is often located behind the front bumper, but on some vehicles can be found in the door mirror behind the glass. It is used to estimate air density and by the air conditioning system – the system will not function if the air outside is too cold.
Common Names for the Temperature Sensor are:
- Cylinder Head Temp Sensor
- Coolant Temp Sensor
- Engine Temp Sensor
Abbreviations often used are: