Skip the auto shop - Our mechanics make house calls

P0520 OBD-II Trouble Code: Engine Oil Pressure Sensor/Switch Circuit Malfunction

diagnostic check engine light

P0520 definition

A P0520 trouble code is related to a vehicle’s engine oil pressure sensor or switch and its associated electrical circuit.

What the P0520 code means

P0520 is a OBD-II generic code for threshold issue with the oil pressure sensor. If the engine computer reads a signal from the sensor that is either too high or too low in relation to the manufacturer’s parameters, a P0520 will be triggered. If a red oil pressure light is associated, there could be a serious mechanical problem as well.

What causes the P0520 code?

The most common causes for a P0520 are:

  • Faulty oil pressure sensor/switch
  • Faulty oil pressure sensor/switch wiring
  • Faulty oil pressure from dirty engine oil
  • Faulty oil pressure from a lack of compression

What are the symptoms of the P0520 code?

Symptoms will vary from nothing more than a check engine light and inoperable oil pressure gauge (if equipped), to rough idling, poor engine performance, excessive engine noise, and even premature engine failure.

How does a mechanic diagnose the P0520 code?

With any oil pressure issue, your mechanic will first visually inspect the engine’s oil and levels. If it’s obvious the oil has surpassed its change interval, it should be changed with a new filter. A visual inspection of the pressure sensor will come next to ensure it is properly seated and the wiring is not damaged. The sensor can be tested using a digital multi-meter before being replaced.

Common mistakes when diagnosing the P0520 code

Not all P0520s are caused by faulty pressure sensors as poor engine maintenance can result in poor oil pressure. It’s important to check for other mechanical failures before replacing parts.

How serious is the P0520 code?

A P0520 can be very serious if the oil pressure is indeed too low or too high. Low oil pressure for example can cause the crankshaft and connecting rod bearings to seize, reducing an engine to a glorified paper weight.

What repairs can fix the P0520 code?

The most common repairs for a P0520 are as follows:

Additional comments for consideration regarding the P0520 code

If you encounter a P0525 with a red, oil light, it’s imperative that you stop the vehicle as quickly and as safely as possible before any catastrophic engine damage results.

Need help with a P0520 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.


Post a question and get free advice from our certified mechanics.


More related articles

How to Transfer a Car Title in Idaho
In order to prove ownership of a car, you must have the title. However, when a car is sold, given away or inherited, the title needs...
Veteran and Military Driver Laws and Benefits in New Mexico
The state of New Mexico offers a number of benefits and perks for those Americans who have either served in an Armed Forces branch...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...

Related questions

Q: Check Engine Light is on - 2012 Nissan Xterra

Anytime a code is stored, it will stay stored and the Check Engine Light will stay on until the ECM memory is cleared. If the problem is fixed, then the light and code should not come back. Many times a...

Q: Car cranks but won't turn over

Hello. This problem could be caused by several different things. You could be out of gas, the fuel pump might be working properly, the timing belt could be broken, there could be an issue with electricity getting to your spark...

Q: Bad oil pressure sensor

A common failure in your vehicle is the oil pressure sending unit. Once the sensor is replaced, these codes should go away. I would ask for help from one of the mechanics at YourMechanic to replace your oil pressure sensor...