Jeep Grand Cherokee P0520: Oil Pressure Switch/Sensor → Circuit

Common OBD2 trouble codes include P0520.  It’s generic, which means that it has the same meaning for the Jeep Grand Cherokee as it would any other vehicle.  P0520 indicates that the oil pressure sensor is operating outside of its normal “range”.  This is usually caused by either a defective oil pressure sensor switch, or wiring problems.

Your Grand Cherokee’s oil pressure sensor measures the oil pressure mechanically, and converts that reading into a voltage signal that the ECM (Computer) converts into an oil pressure reading.  This signal triggers an oil warning light.

A serious problem could arise if the red oil warning lamp is lit.  It is possible for the oil pressure sensor to be bad.  If there's no oil pressure, then P0520 could occur.

The P0520 Quick Facts

• Oil pressure sensors are the most frequent cause.
• You can also get it from low oil pressure.
• If you hear knocking or have the low oil pressure light, don’t drive until P0520 is diagnosed.
• Related to P0521.

P0520 Symptoms:  Jeep Grand Cherokee

Other than the check engine lights, there are rarely any symptoms.  You may have low oil pressure if your engine makes unusual sounds (clacky or metallic). 

P0520 Causes:  Jeep Grand Cherokee

• Oil Pressure Sensor It is possible that P0520 was caused by an oil pressure sensor. However, it is wise to inspect the oil level and quality as well as the wiring before assuming any responsibility.
• Oil Pressure Sensor Wiring The signal from the oil pressure sensor is P0520. This indicates that there has been a malfunction in the circuit.  This may indicate an issue with wiring.
• Oil: Low, medium or high The first thing that you should do is check to see if there is oil in your vehicle’s engine at all.  The crankcase can give P0520 if the oil level is very low.  This can be fixed by filling the oil with more, clearing the code and resetting the crankcase.  
• Low oil pressure This code will be displayed if the oil pressure is too low.  This code should be visible with an oil light or low readings from the oil pressure gauge. 
• Wrong or dirty oil- If your Grand Cherokee’s oil hasn’t been changed for a long enough period of time, it can interfere with the oil pressure sensor, even if there still is oil pressure.

Grand Cherokee P0520 Diagnosis

Below are steps to help a mechanic diagnose the problem manually in your Jeep Grand Cherokee.  

1. Examine the oil

Check the oil level first.  If it’s full make sure that it looks healthy.  The oil pressure sensor may be affected if the oil appears blackened or gritty.  If the vehicle is past it’s oil change deadline (regardless of how the oil looks), changing the oil would be a good idea.

2. Examine the Wiring Harness

Next, you should inspect the wiring harness running from the oil pressure sensor to the ECM.  You could have P0520 if the wiring is damaged.  Don’t forget to make sure that the harness is still plugged into the sending unit and undamaged.  

This code can be thrown for many reasons, including wiring issues.  The wiring is close to the Grand Cherokee’s exhaust and can get brittle over time.

3. Manually check your oil pressure

If the wiring and oil levels are in good condition, you can manually test the oil pressure.  There are two options: Manual oil pressure gauge to see if it’s where it needs to be.  They're easy to use.  Here’s a Great YouTube Video That will explain exactly how to use the gauge for checking.

If the oil pressure from the gauge reads ok, you’ll need to replace the oil pressure sending unit/sensor.  If there is low or no oil pressure, you’ll need to figure out why.

Conclusion:  P0520 Jeep Grand Cherokee

It is easy to diagnose P0520.  If the oil light comes on, make sure you check that your oil pressure is correct.  You will be successful in fixing Grand Cherokee.