Description And Operation
It is an NTC type (Negative Temperature Coefficient) sensor. The coolant temperature sensor is used by the Engine Management Node to calculate the engine temperature.
To obtain this information it uses the sensor element's ability to vary its resistance according to the temperature. The engine temperature sensor is fitted on the thermostat.
| 1. | NTC resistance |
| 2. | Sensor body |
| 3. | Electrical connector |
The reference voltage of the NTC element is 5 V; because the Engine Management Node input circuit is designed as a voltage divider, this voltage is divided between a resistance in the Engine Management Node and the NTC resistance of the sensor. Thus the Engine Management Node is able to evaluate the sensor resistance variations through the changes in voltage and is able to obtain the temperature information.
Variable resistance from a maximum of 48 kohm at -40°C to 66 ohm at 140°C.