Possible causes

– Faulty Engine Oil Temperature sensor
– Engine Oil Temperature sensor harness is open or shorted
– Engine Oil Temperature sensor circuit poor electrical connection

When is the code detected?

The P0198 indicates the Engine Oil Temperature Sensor signal voltage is hign (low temperature).

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)

P0198 INFINITI Description

The engine oil temperature sensor is used to detect the engine oil temperature. The sensor modifies a voltage signal from the Engine Control Module (ECM). The modified signal returns to the ECM as the engine oil temperature input. The sensor uses a thermistor which is sensitive to the change in temperature. The electrical resistance of the thermistor decreases as temperature increases.