P0520 — Engine Oil Pressure Sensor/Switch Circuit
Moderate severityWhat it means
P0520 is stored when the engine control unit sees a fault involving the engine oil pressure sensor/switch circuit. The oil pressure sensor or switch reports whether the engine has enough oil pressure; the control unit uses it for the warning light and, on some engines, for variable valve timing. The control unit has flagged this circuit or signal as outside its normal operating range.
Common symptoms
- Oil pressure warning light
- A gauge that reads wrong or erratic
- Possible VVT-related codes
Likely causes
- A wiring, connector or ground problem in the circuit
- A failed sensor or actuator in the circuit
- A faulty oil pressure sensor/switch
- A wiring or connector fault at the sensor
What to check first
- Inspect the connector and wiring for damage, corrosion or loose pins
- Confirm actual oil pressure with a mechanical gauge before trusting the code
- Inspect the sensor connector and wiring
Can you keep driving?
If real oil pressure is low, stop driving immediately to avoid engine damage; if only the sensor is faulty it is less urgent — but verify first.
Frequently asked questions
What is the most common cause of P0520?
The most likely cause is: A wiring, connector or ground problem in the circuit. Several other faults can set P0520 as well, so confirm the real cause with live data and the checks above before replacing any parts.
Can I just clear P0520 and keep driving?
Clearing P0520 with an OBD2 scanner turns the warning light off, but if the underlying fault has not been repaired the code will usually come back within a few drive cycles. Fix the cause first, then clear the code to confirm the repair worked.
How serious is P0520?
P0520 is a moderate-severity code. The car is often still drivable, but have it diagnosed soon — the underlying problem can get worse and it may fail an emissions test.
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All information, explanations and guidance on this page are general preliminary information only. They are estimates and may be entirely wrong, incomplete or inaccurate, or may not apply to your vehicle at all. Never take any action based on this content alone — do not decide to keep driving, clear codes, replace parts, repair or otherwise work on your vehicle based only on what you read here. In every case, and for any final decision, you must consult qualified technical personnel (a professional mechanic, an authorized service centre or an engineer) and obtain their approval before acting. MechanicAI accepts no liability or responsibility whatsoever for any damage, fault, injury, loss or outcome that may arise — directly or indirectly — from using or relying on this information, for any reason and under any circumstances. By using this page you acknowledge and accept these terms.