Guide To P0520 OBD Error Code Solutions

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Are you experiencing rough idles with engine stalling and not starting on many occasions? Is the Check Engine Light illuminated and you notice affected fuel economy with rattling noise from under the hood? All this can be an indication of problem with the fuel injection system and thus can store and flash P0520 error in the Powertrain Control Module (PCM).

OBD II fault code P0520 is a generic code that is defined as “Engine oil pressure sensor/switch -circuit malfunction”, and is set when the PCM (Powertrain Control Module) detects either an actual low oil pressure condition, or a malfunction in the oil pressure switch and/or its control circuit.

The oil pressure switch is a simple pressure switch that is fed with a reference voltage by the PCM. The pressure-sensing mechanism in the switch is in direct contact with the oil circulating through the engine, and since changes in oil pressure produce either a decrease or increase in the oil pressure switch resistance, the PCM is able to “convert” the changes in resistance into a reasonably accurate representation of the actual oil pressure at any given moment and engine speed.

The PCM in any given application is programmed to recognize a range of signal voltages (that roughly correspond to actual oil pressure(s)) that represent the acceptable oil pressure range for that application. Thus, when the PCM detects either an abnormally high or low signal voltage, that by extension could indicate an abnormal oil pressure, it will set code P0520, and illuminate a warning light.

What causes this problem with the Engine Oil Pressure Sensor/Switch Circuit?

• Oil pressure switch/sensor faulty
• Burnt, shorted, disconnected, damaged or corroded wiring and/or connectors
• Use of wrong engine oil
• Poor basic preventive maintenance, such a failure to change the oil and oil filter regularly
• Excessive mechanical wear in the engine
• Internal engine components mechanical failure such as (among others), the oil pump, oil pressure relief valve, or even timing chain tensioners and/or guides
• Failed or failing powertrain control module

1. Timing Chain Tensioner - Faulty tensioner can cause rattling noise from the timing area and cause performance issues under load. Thus, replace bad tensioner now!
2. Oil Pressure Relief Valve - If the pressure valve is faulty, it can cause extreme damages to filters and engine itself. Buy new pressure relief valve and replace the old one now!
3. Oil Pressure Sensor - Faulty sensor will send wrong data to the PCM causing performance issues. Thus, replace damaged sensor now!
4. Engine Oil - Use the correct engine oil as per specifications and replace if needed. Buy new engine oil and replace it now!
5. Oil Filter - Check for damaged oil filter and replace it if needed. Buy new oil filter today!
6. Powertrain Control Module - P0520 error code also relates to problems with the PCM. This can cause improper engine and throttle response. Replace faulty PCM now.
7. Oil Pump - Check if the oil pump is functioning properly or not. Replace faulty oil pumps now!
8. Oil Level Sensor Connector - Check if the sensor connectors are connected properly and are not damaged. If found so, replace it immediately.
9. Diagnostic Tool - Use professional scanning and diagnostic tools to detect the OBD error code. Buy from us now!

It is essential to know the symptoms of an issue as only then you would be able to solve the problem. So that’s why we have listed out some major symptoms of OBD Code P0520 here:

Common Symptoms

• Low or High Oil Pressure Gauge Reading
• Malfunction Indicator Lamp (MIL) illuminated
• Illuminated Oil Pressure Warning Light
• Excessive Engine Noise and Premature Engine Failure
• Poor Engine Performance and Rough Idling

Here are some ways with the help of which you will be able to correct the OBD Code P0520.

• Oil pressure sensor replacement
• Oil pressure sensor wiring replacement
• Engine oil and filter replacement

There is no need to be anxious as Parts Avatar – Car Parts Online is here to help you out! We have high grade Timing Chain Tensioners, Oil Pressure Relief Valve, Oil Pressure Sensor, Engine Oil, Oil Filter, Powertrain Control Module, Oil Pump, Oil Pressure Sensor Connectors and a lot more for our precious customers.

Here are some steps which you should follow in order to diagnose this fault code:

• Make use of a suitable OBD-II scanner (or code reader), a digital volt/ohmmeter, and a manual oil pressure gauge which will be most helpful in performing a successful diagnosis. Begin with a visual inspection of all wiring and connectors.
• Repair or replace damaged, disconnected, shorted, or corroded wiring, connectors, and components as necessary.
• Retest the system after repairs are completed to ensure success. If all system wiring, connectors, and components (Including fuses) appear to be in normal working order, connect the scanner (or code reader) to the diagnostic connector and record all stored codes and freeze frame data. This information can be extremely helpful in diagnosing intermittent conditions that may have contributed to this code being stored
• Clear the code and operating the vehicle to see if it returns. This will help to determine whether or not the malfunction is intermittent. After the codes are cleared, test drive the vehicle to see if the code returns. If the code fails to immediately return, you may have an intermittent condition
• Intermittent conditions can prove to be quite a challenge to diagnose and in extreme cases may have to be allowed to worsen before a correct diagnosis can be made.
• If engine oil pressure is excessive, suspect a faulty oil pressure sensor or clogged oil filter. Make sure that the engine is filled to the proper level with suitable engine oil. To diagnose the low oil pressure condition, connect the scanner or code reader and make a note of all stored trouble codes and applicable freeze frame data. Clear the codes and shut the engine off. Connect the manual oil pressure gauge to the engine.
• Next, start the engine and check for leaks Allow the engine to reach normal operating temperature and make a note of the actual oil pressure reading at idle, 1,200 RPMS, and 2,500 RPMs. Compare your findings with the manufacturer’s specifications and make engine repairs as necessary.
• Compare your findings with manufacturer’s specifications and repair open or shorted wiring as necessary. PCM failure is rare as a cause of this condition but should be replaced or reprogrammed as required.

Common Mistakes When Diagnosing the P0520 Code

Most of the time we tend to diagnose the problem without completely identifying the real cause of it. It is important to follow all the diagnostic steps and examine each component carefully before correcting. Some of the components to be focused on are listed below;

Clogged fuel filter

• Fuel pressure regulator failure
• Fuel pump/injector failure
• Leaking fuel lines
• Powertrain Control Module (PCM) failure
• Wiring/harness issue