In most cases, you should not rely on a P0520 code as a green light to keep driving. P0520 signals a problem with the oil pressure sensor/switch circuit, or potentially actual low oil pressure, both of which can lead to engine damage if ignored. Treat it as a warning and have the vehicle diagnosed as soon as possible.
This article explains what the P0520 code means, the safety implications of driving with it, practical steps you can take right away, and how technicians diagnose and fix the underlying issue.
What P0520 Means and Why It Matters
The code P0520 stands for Oil Pressure Sensor/Switch Circuit Malfunction. It indicates the engine control module has detected an abnormal signal from the oil pressure sensor or its related wiring. The abnormal signal could reflect actual low oil pressure—dangerous for the engine—or a faulty sensor, connector, or wiring that misreports pressure. Because oil pressure is critical for lubricating moving parts, a false reading or a real shortage can lead to accelerated wear or failure if the car is driven extensively.
Common causes of P0520 include:
- Faulty oil pressure sensor or switch
- Damaged or corroded wiring and connectors
- Poor sensor-to-PCM electrical connections
- Actual low oil pressure due to low oil level, worn engine bearings, failing oil pump, or excessive engine wear
- Oil sludge or contamination causing intermittent sensor readings
Diagnosing P0520 typically involves verifying oil level and condition, performing a live data readout to check sensor values, testing oil pressure with a mechanical gauge, inspecting wiring and connectors, and considering a PCM/software update if a known defect exists in the vehicle's software.
Should I Drive Now? Immediate Safety Steps
Before taking action, it's important to understand the risk. If the oil pressure actually falls below safe limits, continuing to drive can cause catastrophic engine damage. If the issue is simply a faulty sensor or wiring, you may still be able to drive to a repair shop, but with caution and minimal distance.
Here are practical steps to take right away if you see P0520 on your dash:
- Safely pull over as soon as you can do so without endangering yourself or others, especially if an oil pressure warning light is on or you hear tapping or knocking coming from the engine.
- Turn off the engine and inspect the oil level once it has cooled; check for visible leaks or signs of oil contamination.
- If the oil level is low, add the correct grade of oil and recheck; if you’re unsure, call roadside assistance rather than driving.
- Check for any warning lights or unusual engine behavior when restarting; if the warning persists or you notice abnormal noises, do not drive and have it towed to a shop.
- Schedule a diagnostic with a professional technician to determine whether the problem is sensor-related or a real oil pressure issue and replace faulty components as needed.
Concluding: In practice, treat P0520 as a potential safety issue. If you cannot confirm oil pressure is within spec with a mechanical gauge, do not press your luck by driving long distances. A tow to a repair facility is often the safer option.
What to Expect When You Take It to a Shop
At a repair facility, technicians will typically verify whether there is truly low oil pressure or if the sensor is faulty. This often involves measuring oil pressure with a mechanical gauge, inspecting wiring and connections to the sensor, and possibly replacing the sensor or wiring harness. If real low pressure is found, the engine may require more extensive repairs or parts replacement to prevent damage.
Emergency vs Non-Emergency Scenarios
If you notice a bright oil pressure warning light, loud engine noises, or a rapidly dropping oil level, treat it as an emergency and avoid driving. If the sensor is suspected but oil pressure appears normal on a mechanical test, the car may be moved a short distance to a shop, but only with caution and minimal driving.
Summary
The P0520 code signals a problem with the oil pressure sensor/switch circuit, or potentially actual low oil pressure. It is not safe to ignore, and driving long distances is discouraged until a diagnosis confirms whether the pressure is truly low or the sensor/wiring is faulty. Start with checking oil level and condition, then seek a professional diagnostic to determine the correct fix, which could range from sensor replacement to more substantial engine repairs.
How much does it cost to fix a P0520 code?
Module repair is often temporary; replacement of the affected control module typically costs $600‑$900 plus $200‑$300 labor.
How do I fix the P0520 code?
Fixes and Repairs for a P0520 Code
- A bad oil pressure switch can be removed and a new one installed.
- Low engine oil or a clogged oil filter often necessitates an oil change.
- Damaged wiring can be repaired using a soldered connection and heat shrink.
How long can I drive with a P0520 code?
It is firmly not recommended to drive your vehicle for any period if presented with the P0520 or its related codes.
How serious is the P0520 code?
Driving with the P0520 code is not recommended. While the error code could simply be the result of a faulty signal and the engine may still run, inaccurate oil pressure readings could also mask actual oil pressure issues, increasing the risk of severe engine damage.