Oil Temperature Sensor/Switch: Description and Operation

Oil Pressure Sensor Removal:

Engine Oil Temperature Sensor Circuit:

Purpose:
The Oil Temperature Sensor provides the ECM with information regarding oil temperature. The ECM processes the information to control A/C clutch and engine cooling fan. This information is also utilized by the Central Control Module (CCM) for use in determining when to change the engine oil.

Operation:
The ECM supplies a 5 volt signal to the engine oil temperature sensor through a resistor in the ECM and measures the voltage. The voltage will be high when the engine oil is cold, and low when the engine oil is hot. By measuring the voltage, the ECM knows the engine oil temperature.

Location:
The engine oil temperature (EOT) sensor is a thermistor mounted in the left rear of engine above the oil filter. Low engine oil temperature produces a high resistance, while high temperature causes low resistance.