P0520
Engine Oil Pressure Sensor/Switch Circuit
- Severity
- High
- Driving
- Short journeys only
A fault in the engine oil pressure sensor or switch circuit. The module has lost its reading, which means the oil pressure warning system cannot warn you. The pressure itself may be perfectly fine - but you no longer have any way of knowing, and oil pressure is the one thing you cannot afford to be wrong about.
Possible causes
- CommonLow engine oil level
- CommonFailed oil pressure sensor or switch
- CommonCorroded or oil-contaminated connector at the sensor
- CommonWiring damage - the sensor sits low on a hot engine
- PossibleOil of the wrong grade, or long overdue for changing
- PossibleWorn oil pump, blocked pickup screen or worn bearings
What you might notice
- Oil pressure warning light
- Gauge reading zero or implausibly high
- Ticking or rumbling from the engine
- Check engine light on
- Often no symptom if only the sensor has failed
What to check, in order
- Check the oil level first. It costs nothing, it is the most common cause, and it is the one thing you must not skip.
- Inspect the connector at the sensor for oil contamination - a leaking sensor seal fills its own plug and produces an electrical fault from a mechanical leak.
- Check the wiring for chafe and heat damage.
- Confirm the actual pressure with a mechanical gauge before dismissing this as a sensor fault. That measurement is the only thing that separates a lying sensor from a dying engine.
Read this code from your own car
Plug an ELM327 adapter into the OBD-II port under the dashboard. Pin16 reads every stored, pending and permanent code, explains each one like this page does — offline, with no account — and shows what the car recorded when the fault was set.
Where this code sits
P00xxP01xxP02xxP03xxP04xxP05xxP06xxP07xxP08xxP09xxP0AxxP0BxxP0CxxP0DxxP0ExxP0FxxP10xxP11xxP12xxP13xxP14xxP15xxP16xxP17xxP18xxP19xxP1AxxP1BxxP1CxxP1DxxP1ExxP1FxxP20xxP21xxP22xxP23xxP24xxP25xxP26xxP27xxP28xxP29xxP2AxxP2BxxP2CxxP2DxxP2ExxP2FxxP30xxP31xxP32xxP33xxP34xxP35xxP36xxP37xxP38xxP39xxP3AxxP3BxxP3CxxP3DxxP3ExxP3Fxx
Vehicle speed control, idle control and auxiliary inputs
P0500P0501P0502P0503P0504P0505P0506P0507P0508P0509P0510P0511P0512P0513P0514P0515P0516P0517P0518P0519P0520P0521P0522P0523P0524P0525P0526P0527P0528P0529P0530P0531P0532P0533P0534P0535P0536P0537P0538P0539P0540P0541P0542P0543P0544P0545P0546P0547P0548P0549P0550P0551P0552P0553P0554P0555P0556P0557P0558P0559P0560P0561P0562P0563P0564P0565P0566P0567P0568P0569P0570P0571P0572P0573P0574P0575P0576P0577P0578P0579P0580P0581P0582P0583P0584P0585P0586P0587P0588P0589P0590P0591P0592P0593P0594P0595P0596P0597P0598P0599