What does P0520 mean?
The oil pressure sensor or switch reports engine oil pressure to the computer and the dash gauge or warning light.
The computer has detected an electrical fault in the sensor circuit.
Codes are a starting point. They tell you which test failed, not which part to replace. Check for other stored codes and fix those in a sensible order.
Symptoms
- Check engine light
- Oil pressure gauge erratic or reading zero
- Oil warning light
Common causes
- Open or shorted wiring
- Corroded or loose connector
- Failed sensor
- Blown fuse or reference voltage issue shared with other sensors
How to diagnose P0520
- Look for other codes that share the same 5 V reference circuit.
- Inspect the connector and wiring, then check reference, ground and signal voltages.
- Replace the sensor only after the wiring tests good.
- Check the oil level right away.
- Confirm real pressure with a mechanical gauge before replacing anything.
How to fix it
- Top up oil
- Replace the oil pressure sensor
- Repair wiring
- Repair the engine if real pressure is low
Estimated repair cost
Likely repairs for P0520 run from about $100 to $300, depending on the cause.
| Repair | Typical range (parts + labor) |
|---|---|
| Diagnostic fee (scan + testing) | $100 - $200 |
| Oil pressure sensor/switch | $100 - $300 |
These are rough US estimates for an independent shop in 2026, based on typical parts prices and standard labor times. Dealers, big trucks, luxury brands and high-cost areas often run higher. They are not quotes. Use the repair cost estimator to adjust for your vehicle.
How serious is P0520?
High severity
If the oil light is on, stop and check the oil level. Driving with real low oil pressure can wreck the engine in minutes.
P0520 FAQ
What does P0520 mean?
P0520 stands for "Engine Oil Pressure Sensor/Switch "A" Circuit". The oil pressure sensor or switch reports engine oil pressure to the computer and the dash gauge or warning light.
Can I drive with a P0520 code?
If the oil light is on, stop and check the oil level. Driving with real low oil pressure can wreck the engine in minutes.
How much does it cost to fix P0520?
It depends on the cause. The likely repairs for P0520 range from about $100 to $300 at an independent shop in the US, plus a diagnostic fee of roughly $100-$200. These are rough estimates; dealer prices and some vehicles run higher.
What is the most common cause of P0520?
The most common causes are: open or shorted wiring; corroded or loose connector; failed sensor.