P0195Engine Oil Temperature Sensor A Circuit
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- The engine oil temperature sensor A is an NTC thermistor fed with 5 V through a resistor: the hotter the oil, the lower the signal voltage. The engine module uses the oil temperature for variable cam timing (Ford disables it with cold oil or a sensor fault), engine protection and the oil life monitor; many engines have no such sensor and use a calculated oil temperature instead. P0195 is the general circuit fault without telling low from high. With analogue sensors most manufacturers use P0197/P0198 instead. The documented use is Ford's 2023 diesels with a digital SENT oil temperature sensor: P0195 is set when the sensor reports a status or data fault for 5 s, while a complete loss of communication is U0667. The module then uses a substitute value (Saab: 100 °C), and functions relying on oil temperature are restricted.
- What you may notice
- Check engine light on (depending on manufacturer)
- Oil temperature display missing or fixed
- Restricted cam timing, slightly reduced power
- Oil life calculation less accurate
- Likely causes
- LikelyConnector or harness damaged, corroded or oil-soaked
- PossibleSensor faulty internally (electronics fault on SENT sensors)
- Possible5 V reference or ground problem in the sensor circuit
- RareControl module or software
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Easy · Often possible to do yourself.Typical cost: €40 – €250
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.