What P0195 means
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.
How the engine computer detects it
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 (212 °F)), and functions relying on oil temperature are restricted.
Written from public technical sources and not yet checked by a mechanic. How we write these pages
Symptoms
- Check engine light on (depending on manufacturer)
- Oil temperature display missing or fixed
- Restricted cam timing, slightly reduced power
- Oil life calculation less accurate
Common causes
- Connector or harness damaged, corroded or oil-soaked Most likely
- Sensor faulty internally (electronics fault on SENT sensors) Possible
- 5 V reference or ground problem in the sensor circuit Possible
- Control module or software Less likely
How to diagnose P0195
- Read every stored code with an OBD-II scanner. If misfire or fuel trim codes are there too, fix those first: they often cause this one.
- Inspect the parts involved: engine oil temperature sensor, sensor wiring.
- Work through the causes above from most to least likely, cheapest checks first.
- Clear the code and drive a full drive cycle to confirm the repair held.
Reading the code
- P
- Powertrain
- 0
- Generic (SAE) code
- 1
- Fuel and air metering
- 95
- Specific fault
Questions drivers ask
Can I drive with code P0195?
Usually yes for a short time, if the car drives normally, the temperature gauge reads normal and the check engine light is steady. If the light flashes, the engine loses power or overheats, or other warning lights come on, pull over and have it checked.
Will my car pass an emissions inspection with P0195?
Probably not in states that test vehicles with an OBD-II scan: an emissions-related code that keeps the check engine light on is usually an automatic fail. Rules differ by state and county, so check yours.
Will P0195 clear by itself?
The light can go off after several drive cycles without the fault, but the code returns if the cause is still there. After a repair, the readiness monitors need a full drive cycle before an inspection.
Can I fix P0195 myself?
Often yes, with an OBD-II scanner and basic tools. Difficulty: easy. Start with the cheapest checks before replacing expensive parts.
This page is general information, not a substitute for a professional diagnosis. Repair costs are rough estimates for parts and labor and vary by vehicle and region.