P0520Powertrain
Engine oil pressure sensor circuit malfunction
Where to start
The oil pressure sensor circuit. This code is about the SENSOR, not about the pressure: the unit is complaining about a signal. Even so, start by checking the oil level on the dipstick — it takes a minute and removes the main worry. ⚠️ If the red oil pressure light is on as well, stop the engine at once and do not drive on: oil starvation kills an engine in minutes, not days.
A code is not a diagnosis. It says which check failed, not which part to replace. Clearing it without repair only means the car will report it again in a few trips.
How to put together a report a mechanic will actually read
We have a detailed piece on thisOil pressure: codes P0520, P0521, P0522, P0523, P0524
How the code is built
Letter — the systemPowertrain: engine and transmission
Common or the maker's ownGeneric code: the same on every car
Which part of the engineIdle and auxiliary systems
Number of the faultThe serial number inside that group — it does not say how serious the fault is
All codes in «Idle and auxiliary systems»
How the app helps
CarScan reads this code from your car through an OBD-II adapter, shows whether it is active now or only stored, names the module that reported it, and puts it into a plain-text report for your mechanic.