What it means
The ECU detects a general electrical fault in the engine oil temperature sensor circuit. Signal missing, shorted or out of plausible range.
At a glance
- Usually lights the check-engine light
How it works
The engine oil temperature sensor sends the control module an electrical signal representing oil temperature, which can inform engine protection and control strategies. P0195 sets when the module detects a general fault in this sensor circuit, such as a missing, shorted, or implausible signal.
Common causes
Most likely first.
- Oil temperature sensor failed
- Wiring or connector fault
Symptoms
- Check engine light on
- Oil temperature reading or warning may be abnormal
- Engine performance may be reduced
How to diagnose it
- Review freeze-frame data and scan-tool oil-temperature readings to note whether the signal was missing or implausible when the code set.
- With the ignition off, inspect the oil-temperature sensor connector and nearby wiring for corrosion, loose pins, oil contamination, or damage.
- Check the sensor circuit's supply, ground, and signal continuity using the wiring diagram and manufacturer's specification.
- Compare the sensor reading after a cold soak with coolant temperature and ambient conditions to see whether the signal is plausible.
- If the circuit is intact but the reading remains missing or implausible, test and replace the oil-temperature sensor as indicated by the manufacturer's procedure.
Common fixes
- Reconnect or clean the oil-temperature sensor connector and repair damaged terminals.
- Repair an open, shorted, or damaged section of sensor wiring.
- Restore the sensor circuit's faulty supply or ground connection.
- Replace the engine oil temperature sensor if it fails circuit and plausibility checks.
Can I keep driving?
If an oil-temperature warning appears or the engine is running poorly, stop safely and check the vehicle's oil level and warnings before continuing. Without a reliable oil-temperature reading, the module may not respond correctly to overheating, so avoid heavy loads until diagnosed.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.