Functional description

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 engine oil temperature sensor, whose resistance value drops when the temperature increases.

Fig 1: Engine Oil Temperature Sensor And Two-Pin Plug Connection

Courtesy of BMW OF NORTH AMERICA, INC.

The change in resistance between 217 kΩ to 37 Ω is temperature-dependent and corresponds to temperatures between -55 °C and 155 °C.