P0197-Engine Oil Temperature Sensor Circuit Low: Notes
For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .
Theory of operation
The oil temperature sensor is a variable resistor that measures the temperature of the engine oil. The Powertrain Control Module (PCM) supplies a 5 Volt reference and a ground to the sensors low reference signal circuit. When the oil temperature is low, the sensor resistance is high. When the oil temperature is high, the sensor resistance is low.