P051b Ford F150 | Meaning, Causes And Solution

The Ford F150 has been the top selling pickup truck for decades. It is a reliable choice for its amazing towing capabilities. But considering all the greatness it is still inevitable from certain problems. If you notice the Check Engine Light of your Ford is turned on for the DTC code P051B, you can fix your vehicle by following the instructions that we are going to give in this article.

The Diagnostic Trouble Code (DTC) p051b ford f150 means the Crankcase Pressure Sensor Circuit Range/Performance. The Engine Control Module (ECM) sets the code P015B when it detects electrical values operating outside the range or if there is a performance fault in the crankcase pressure sensor circuit.

If the ECM of your OBD-II vehicle such as the Ford F150 sets this DTC code, then you can easily diagnose the code by simply following the instructions we are going to give throughout the article. So stick with us for all the valuable information regarding the issue.

What Does The Code P015B Mean on Ford F150?

The crankcase pressure sensor lets the Powertrain Control Module (PCM) know how much pressure is generating in the engine.

Excessive pressure can harm the gaskets or seals, so the PCM prevents any gaskets or seals from damages by calculating accurate values provided by the crankcase pressure sensor.

So if the crankcase pressure sensor gets faulty for some reason the ECM will set the code P051B.

  • P = Powertrain (includes engines, transmission and drivetrain accessories) this is what powers the vehicle.
  • 0 = Generic issue reserved by SAE.
  • 5 = Specific system corresponding with the issue. In this case vehicle speed and idle control.
  • 1B = This indicates the particular problem. Which is for this case detecting electrical values outside the range by the ECM.

Common Symptoms Of A P051B on Ford F150

If your Ford is on this code and you are not noticing it then it may become troublesome for you in future. It can cause irreparable damages to your vehicle if not taken care of.

So now we are going to learn some common symptoms that might happen if your Ford truck is on the DTC code P051B. 

Low Fuel Economy 

Your Ford pickup truck might give low fuel economy and less mileage than normal. It can happen for various reasons. So if you notice low fuel efficiency on your truck, it can be because of this code. 

Gaskets Leaking

The gasket leak on your Ford can be a symptom for this DTC code. A gasket leak happens when the coolant of your vehicle leaks.

If it happens then you are likely to see blue fumes coming from the exhaust pipe. Excessive oils entering the combustion chamber are causing the blue fumes.

Reduced Engine Power

Engine powers get reduced when there is lack of flow of fuel or air into the engine. If either of them is being restricted from flowing into the engine then the engine can produce less power.

The DTC code P051B can cause the engine of your Ford to not be able to produce the desired power.

Black Soot Coming Out Of The Engine

If you see black soot coming out of the engine from the exhaust pipe, then it can be a sign of too much fuel being burnt.

It can often happen because of clogged air filters. Allowing dust to enter the engine. This can be a sign that your Ford is on the DTC code P051B. 

Sludge in Engine Oil

Sludge in engine oil can indicate that your Ford F150 is the code P051B. It can happen if the engine oil meets heat or moisture. Dirts getting into the engine oil can also create sludge in engine oil.

It can harm the circulation of the oils in the engine which also causes power loss and overheating. 

Illuminated Check Engine Light

Look for the Check Engine Light (CEL), if it’s illuminated then your engine is on a DTC code. To take your Ford to your nearest garage to find out if you see the CEL is on.

What Are Some Potential Causes Of A P051B Code on Ford F150

Finding out the causes are necessary to find a solution. Till now we have learned about the common symptoms of a P051B code on a Ford F150.

So, now we will know about the potential causes or reasons of the code to appear on your Ford. If you notice any of the causes then you should immediately take action about fixing the problem. 

  • Damaged crankcase pressure sensor
  • Engine Control Module (ECM) issues
  • Clogged PCV (Positive Crankcase Ventilation) valve.
  • Sludgged engine oil

How To Diagnose And Fix P051B Ford F150 Code

We have learned the causes and reasons of a P051B code on your Ford F150. Now, every problem has a solution and we are going to find out the solutions and know how to diagnose each of the causes of the DTC code on your ford. So, let’s go through the thorough instructions on how to diagnose the code.

1. Replace The Damaged Crankcase Pressure Sensor

The crankcase pressure sensor sends a signal to the PCM to let it know how much pressure is in the engine. The PCM seals the gaskets so they don’t get exposed to the excessive pressure.

A damaged crankcase pressure sensor can send false signals to the PCM which can cause the DTC P051B to appear. So, it needs replacement if found damaged.

  1. Locate the crankcase pressure sensor under the engine cover. 
  2. Remove the 2 10mm plastic bolts holding the cover in place.
  3. After removing the engine cover you will see the sensor right beside the oil reservoir.
  4. Uncip both sides of the sensor from the engine by simply unclipping it.
  5. Disconnect the electrical wiring harness from the sensor.
  6. Set the old sensor aside and put the new one in place and connect the electrical wiring harness back to the sensor.
  7. Put the engine cover again and connect the plastic bolts.

After this your crankcase pressure sensor is replaced with a new one. A crankcase pressure sensor for your Ford F150 can cost you $40-$90.

2. Repairing Engine Control Module (ECM) Issue

Engine Control Module (ECM) is a control unit that operates the optimal performance of your Ford’s engine. It also controls ignition timing so the car gets more power and better fuel economy.

Sometimes bad electrical wiring also causes the ECM to fail. So, check if the wiring is the issue and replace the wirings. But if the wiring is ok then the ECM itself is damaged and needs to be replaced.

  1. Open the hood and disconnect the negative batteries.
  2. Locate the ECM which is a silver coloured module.
  3. Disconnect the electrical connections by unclipping it and pulling away from the module.
  4. Remove the screws by using a wrench and pull out the old ECM.
  5. Put the new ECM in place and tighten the screws and bolts. 
  6. Reconnect the electrical wiring and put back everything in place.
  7. Connect the negative batteries again and see if everything is working properly.

The ECM is very expensive, a good quality ECM can cost you around $800.

3. Cleaning The Clogged PCV (Positive Crankcase Ventilation) Valve

The PCV valve vents out the wasted gas from the engine that could not ventilate through the exhaust pipe so it does not make any sludge in the oils in the crankcase. So, a clogged PCV valve can be a cause for your Ford to get the DTC P051B.

  1. Remove the engine cover by unscrewing the 10mm bolts holding it. 
  2. Locate the PCV valve right under the engine’s side of the crankcase sensor.
  3. Remove the crankcase sensor from that side and by using a combination wrench, twist the PCV valve and remove it from its place.
  4. Remove the hose and hose clamp from the valve and bow it through the carburetor cleaner. 
  5. If the valve is still sluggy then it needs replacing. If you see it is cleaned then you can still use the old one.
  6. Put back the cleaned or replaced valve right in the place and make sure it is seated properly. Twist it with the wrench on the other side this time and tighten it.
  7. Put the crankcase sensor back and put the engine cover and tight the bolts.

If you can’t clean the valve and need replacements, then the valve would have cost between $80-$100.

4. Remove Sludge From Engine Oil

The engine oils while oxidation in the engine breaks down into molecules and combines with dirts, water, gasses and coolants. Then it makes a sticky mixture of sludge.

Which cripples the engine’s coolant and ventilations and makes the engine overheat. So if you see sludges in the engine oil then it can be a reason for the code P051B to appear.

The common way to remove sludges from your Ford’s engine and oils is to perform an engine flush. You can buy a chemical additive which removes the sludges.

You need to pour the chemical into the oil filter of your Ford F150. Then idle the engine for 10-15 minutes. After that drain the old oils and pour new one. See if the sludges are removed.

If you still see them then you might need to visit a garage for a complete engine service.

You can buy the aftermarket chemical additive for $10-$15. But if you need to take the truck to a garage then you need to pay for the labor cost.

How To Prevent A P051B Ford F150 Issue From Happening In The Future

By now it is safe to say that you have a very clear idea on how to diagnose the P051B code on your Ford F150. But even if you diagnose it once it can happen again if you are not careful enough.

So now we will try to give some advice on how you can prevent it from happening again in the future.

  • Take your Ford F150 to the garage frequently for full service.
  • Change the air filter and fuel filters after a certain time.
  • Always check if the electrical wirings are functioning properly.
  • Always check for the tire conditions and use tire gel.
  • Check the coolants level and transmission fluid.
  • Use the right grade of synthetic engine oil and change it Frequently. 
  • Change gear oils and lubricators when necessary.
  • Avoid rough roads and off-roading.


Now that we have come to the end of this thread, we believe you got all the information regarding the DTC P051B and the instructions on how to diagnose it. This kind of code can often lead to permanent damages to your Ford. So, taking actions immediately after finding out the problem is essential.

But before starting the diagnosing process, make sure you understand the problem. Don’t just proceed to replace everything, you can consult a technician for finding out the exact reason that is causing this code to appear.

Maintaining the vehicle with proper care is also very essential in order to prevent it from happening again. So in order to get the best performance out of your Ford F150, you should also be very careful.

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