P0520 Engine oil pressure sensor/switch A circuit
What P0520 means
The engine control unit has found a fault in the circuit for the oil pressure sensor or switch. The car can no longer reliably tell you if oil pressure is low, so you lose an important warning.
P0520 is a generic SAE J2012 code: it means the same on every make. The exact cause still depends on the car, so read the freeze-frame data before replacing parts.
At a glance
- Severity
- Medium
- Typical repair cost
- 80–280 €
- Workshop time
- 0.4–1.4 h
- Repair difficulty
- Easy
- DIY possible
- Yes
- Check engine light
- Yes
- Affects emissions test
- No
Parts and labour at an independent workshop in Europe. Main dealers charge more; the cause decides the bill, not the code.
Symptoms
- Oil pressure warning light on, flickering or not working
- Oil pressure gauge reading zero or maximum
- Check engine light on
Common causes
- Faulty oil pressure sensor or switch
- Oil-soaked, loose or corroded connector
- Damaged wire to the sensor
- Genuinely low oil pressure on some cars that report it under this code
Can I keep driving with P0520?
Check the oil level before driving further. If the level is correct and the engine sounds normal, you can drive carefully and have it checked within one to two weeks; if the red oil light is on with low oil or engine noise, stop the engine.
What to check first
- Check the engine oil level and top up if needed
- Inspect the sensor connector and wiring for oil leaks and damage
- Have the real oil pressure measured with a mechanical gauge
- Replace the sensor or repair the wiring
Related codes
- P0521 Engine oil pressure sensor/switch A range/performance
- P0522 Engine oil pressure sensor/switch A low
- P0523 Engine oil pressure sensor/switch A high
- P0510 Closed throttle position switch
- P0530 A/C refrigerant pressure sensor A circuit
- P0532 A/C refrigerant pressure sensor A circuit low
- P0533 A/C refrigerant pressure sensor A circuit high
- P0507 Idle control system RPM higher than expected
Data: TORKO fault-code catalogue, built on OBDex (CC0-1.0) and reviewed against workshop practice. Informational only — it does not replace a diagnosis by a mechanic.
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