Code 52, Low Engine Oil Temperature: Notes

Fig 1: Code 52, Schematic, Low Engine Oil Temperature

Fig 2: Code 52, Flow Chart, Low Engine Oil Temperature

The engine oil temperature sensor is a thermistor, similar to a coolant or air temperature sensor. When engine oil temperature is cold, sensor resistance is high, therefore, ECM will see a high monitored voltage signal on circuit No. 901. As temperature increases, resistance decreases and the ECM sees a lower monitored voltage on the circuit.

Test Number 1)  Code 52 will set if engine oil temperature sensor indicates less than -31°F (-35°C) and engine has been running for more than 30 minutes.

Test Number 2)  Code 52 will set when open occurs in sensor, wire or connection. This determines if the ECM and wiring are okay.

Test Number 3)  Determines if the engine oil temperature signal or sensor ground circuit is open.