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Functional description

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A temperature-dependent electrical resistor is used for temperature sensing. The circuit contains a voltage divider where the resistance can be measured depending on the temperature. A temperature is converted using a characteristic curve specific to the sensor. An NTC resistor (NTC) is installed in the coolant temperature sensor, whose resistance value drops when the temperature increases.

Fig 1: Identifying Coolant Temperature Sensor And Plug Connection
G09908780Courtesy of BMW OF NORTH AMERICA, INC.
Item Explanation
1 Coolant temperature sensor
2 two-pin plug connection

The resistance changes from approx. 216 kΩ to 33 Ω depending on temperature, which corresponds to a temperature of -55 °C to 160 °C.