What Does P051B Ford F150 Mean & How To Fix It?

What does P051B Ford F150 mean? It means the electric values are running above or lower range than the crankcase pressure sensor requires.

There can be many reasons why this code can pop up in your OBD-II vehicle, including electric issues, sludge oil, clogged PCV system, and more.

In the following discussion, we’ll discuss these reasons and solutions elaborately. You should solve this error code issue after applying our possible solutions.

Causes And Solution of P051B Ford F150 Error Code

From the P051B Ford Expedition 2015 to P051b Ford Expedition 2017 the reason behind this error code remains the same. It’s a powertrain diagnostic generic trouble code and usually appears on OBD-II vehicles, for example, Ford.

There can be multiple reasons why you may see this error code on your Ford F150. Below are some common causes of the p051b code ford f150 and their possible solutions:

Faulty crankcase pressure sensorLess fuel economy
Electrical issuesGasket leaks
Flawed PCV valveIlluminated CEL (check engine light)
Sludge oilPerformance issue with the engine
Clogged PCV system
Build-up of sludge
Black soot coming from the engine

Now, we’ll elaborately discuss all the P051B DTC problems and their solutions.

Faulty Crankcase Pressure Sensor

The purpose of the crankcase pressure sensor is to track the engine oil’s pressure in the crankcase.

And when anything goes wrong, or the pressure range falls too low or increases too high, the crankcase will send a warning signal; therefore, you can see the error code.

Usually, you should see illuminated check engine light as a warning in the first place.

Solution: Inspect the oil pressure on the engine and try to figure out if there’s any problem with it. If everything is fine, then the crankcase pressure sensor has some issue, consider taking your Ford to professionals.

Electrical Issues

Here comes another reason behind the code p051b ford f150 issue. Since everything inside a car runs through electric components, it’s possible that you may see the error code due to some electrical fault in the internal system.

Solution: Run a thorough visual inspection on the electrical connection and look for damaged wire. Once you detect the damaged wire, consider repairing or replacing it to remove the error code.

Flawed PCV Valve

The PCV (positive crankcase ventilation) is a one-way valve attached to the crankcase. The crankcase in your Ford F150 holds motor oil. This component is located at the end of the engine, and when the engine burns fuel, the valve fabricates gasses.

Read Also: TBC Fault (What & Why): A Complete Experts Guide+ How To Fix!

When the valve is bad, you may notice black soot coming from the engine or bad engine performance besides the P051B error code.

Solution: If your vehicle has a flawed PCV valve, you must repair or replace the valve to get rid of the error code.

Sludge Oil

You shouldn’t ignore this issue at all. Oil sludge is basically a thick gel formed through oil oxidation and contamination. Fuel burns, dirt, and metal fragments are responsible for this contamination. It’s dangerous to drive your vehicle with sludge oil, and your car won’t be able to lubricate the moving parts adequately.

On the other hand, when your engine will hold build-up sludge, it will reduce the performance of the engine.

Solutions: To fix this issue, you need to change the oil. Make sure the new oil is completely clean.

Clogged PCV System

If the hose or the PCV system is clogged, you’re most likely to see the P051B Ford Fusion error code in your vehicle. This issue will make the crankcase store the oil in the combustion chambers. As a consequence, the oil will burn inside the engine and run out from the exhaust pipe.

A clogged PCV system can produce oil contamination, high consumption of fuel, sludge build-up, and so on.

Solution: Get a carburetor cleaner and break the blockage by tossing the tool. This way, you should clean the gunk and remove all the issues, including the error code.

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Frequently Asked Questions (FAQs)

What does code P051B mean?

It’s a diagnostic trouble code on vehicles Ford, Dodge, Nissan, Jeep, etc. the P051B refers to crankcase pressure sensor circuit performance or range. Your vehicle will set the error code P051B when the PCM detects that the electrical values are working outside the required range of the pressure sensor circuit.

How much does it cost to replace the crankcase pressure sensor?

A new crankcase pressure sensor will cost between $40 to $90, and you may need to spend between $150 to $170 to replace the sensor, including the labor cost.

How do I lower my crankcase pressure?

To lower the crankcase pressure, you need to seal the engine from the cylinder pressure efficiently. Another way to reduce the pressure is to reduce the ring end spacing by custom setting the top two rings to fit the engine’s way to run.


The code P051B Ford F150 can be fixed quickly if you can figure out the exact reason behind the problem. You can reduce the labor cost of replacing the crankcase pressure sensor by doing it yourself, as it isn’t a difficult task.

However, though it’s not dangerous to drive your vehicle with P051B, we would still suggest you fix the problem first.

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D Conroy

Meet our senior writer and content manager of Automasterx. He has worked in several mechanical garages and mastered different vehicle diagnoses and parts repair. He never stops until finding out the ultimate solutions for any vehicle fault code. However, ensuring the only solid solutions for each vehicle malfunction is his core part of the duty, alongside analyzing fault codes and signals.

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