Ford Falcon P0520: Oil Pressure Switch/Sensor → Circuit

The OBD2 code P0520 can be used to indicate trouble.  It’s generic, which means that it has the same meaning for the Ford Falcon 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 Falcon’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.

Red oil alert lights are a sign of a problem.  It is possible for the oil pressure sensor to be bad.  When there is no oil pressure, P0520 may occur.

The P0520 Quick Facts

• Most common is an oil pressure sensor.
• Low oil pressure can cause it.
• If you hear knocking or have the low oil pressure light, don’t drive until P0520 is diagnosed.
• Similar to P0521.

P0520 Symptoms:  Ford Falcon

Sometimes, there are no symptoms (apart from the check engine lamp).  You may have low oil pressure if your engine makes unusual sounds (clacky or metallic). 

P0520 Causes:  Ford Falcon

• Oil Pressure Sensor It is possible that P0520 was caused by an oil pressure sensor. However, it would be 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.
• You can have low or no oil 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.  Clear the code and fill up the oil.  
• Low oil pressure This code will be displayed if the oil pressure is too low.  The oil light should indicate that it is present, as well as a reading of low oil pressure from the gauge. 
• Wrong oil or dirt? If your Falcon’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.

Falcon P0520 Diagnosis

Below are steps to help a Ford Falcon mechanic diagnose the problem manually.  

1. Take a look at the oil

Check the oil level first.  If it’s full make sure that it looks healthy.  It may have a problem with the oil pressure sensor if it is darkened or stained.  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. Check the Wiring Harness

Next, you should inspect the wiring harness running from the oil pressure sensor to the ECM.  It could also be the cause of P0520.  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 Falcon’s exhaust and can get brittle over time.

3. You can manually check the oil pressure

After confirming that both the wiring and the oil level are fine, it is time to check the oil pressure manually.  A Manual oil pressure gauge to see if it’s where it needs to be.  These gauges are very easy to use.  Here’s a Amazing 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 Ford Falcon

It is easy to diagnose P0520.  If the oil light comes on, make sure you check that your oil pressure is correct.  Have fun fixing your Falcon