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P0195 — Engine Oil Temperature Sensor Circuit

Generic OBD-II · all makesPowertrain (engine & transmission)

The code indicates the engine control module is receiving a voltage from the oil temperature sensor that is higher than expected, suggesting a problem with the sensor circuit.

Symptoms

What causes it — most likely first

1. Faulty oil temperature sensor

The sensor itself can fail and output a voltage that is consistently high, triggering the circuit high input code.

2. Open or short in sensor wiring or connector

Damaged wiring, corrosion, or a short to voltage can cause an abnormally high signal on the sensor circuit.

3. Excessive engine oil temperature

If the oil overheats beyond design limits, the sensor may report a high voltage, though this is usually accompanied by other overheating symptoms.

4. Problem with the engine control module input circuit

A rare failure of the PCM's sensor input circuitry can misinterpret the sensor signal as high, but this is less common than sensor or wiring faults.

How it's diagnosed

  1. Use a scan tool to confirm the P0195 code and check for any related codes.
  2. Inspect the oil temperature sensor wiring harness and connector for corrosion, breaks, or loose pins.
  3. Measure the sensor resistance at known temperatures (e.g., cold and hot) to verify proper operation.
  4. Monitor the sensor voltage with a multimeter while the engine warms up to see if it stays abnormally high.
  5. If sensor and wiring test normal, test the PCM input circuit for continuity and proper voltage reference.

Code facts & related codes

SystemPowertrain (engine & transmission)
StandardizationSAE generic — identical on every make

Frequently asked

Do I need to replace the PCM when P0195 appears?

No. The PCM is rarely the cause; most often the issue is a faulty sensor, wiring, or connector.

Can a bad oil temperature sensor affect engine performance?

It can cause the PCM to limit power or trigger an overheating warning, but the engine usually continues to run normally.

Is it safe to drive with this code?

If the oil temperature gauge shows normal levels and no overheating symptoms are present, short‑term driving is generally safe, but the issue should be repaired promptly.

Will a low oil level cause P0195?

Low oil level can lead to overheating, which might cause the sensor to read high, but the code itself is triggered by an electrical fault rather than oil level directly.