OBD-II · Engine and powertrain (P)
P0521
Engine oil pressure sensor/switch range/performance
What it means
The oil pressure reading does not match what the ECU expects for the engine speed and temperature. It can be a sensor fault or a real oil pressure problem.
Symptoms
- engine warning light
- oil pressure warning may flicker or stay on
- possible wrong oil pressure reading
Likely causes, most likely first
| No. | Cause |
|---|---|
| 01 | faulty oil pressure sensor or switch |
| 02 | wrong oil viscosity or old, degraded oil |
| 03 | low oil level |
| 04 | fault in the variable (two-stage) oil pump control |
| 05 | worn oil pump or engine bearings |
What to check, step by step
- 01If the red oil pressure warning is on, stop the engine and check the oil level before driving further
- 02Check the oil level and that the correct oil grade is used
- 03Inspect the sensor or switch connector and wiring (oil leaking into the connector is common)
- 04Confirm the real oil pressure with a mechanical gauge in place of the sensor
- 05Replace the sensor or switch if the real pressure is correct