What Is P0405 Code On 6.0 Powerstroke: How To Fix?

Ford 6.0L Powerstroke PCM brings up many error codes defining the inner difficulties of the engine. The P0405 is one of the error codes & it’s related to the exhaust gas recirculation (EGR) system. 

If you’re having troubles with the P0405 & don’t know what to do about it, this article is for you. In this article, I’ll be explaining the root causes & fixing procedures of this code with minimal household equipment. 

What Does P0405 Code Means On 6.0L Powerstroke? 

P0405 is one of the diagnostic trouble codes (DTCs) of the Ford 6.0L Powerstroke. By definition, this trouble code refers to Exhaust Gas Recirculation Sensor Circuit A Low. 

The exhaust Gas Recirculation (EGR) system helps keep the nitrogen oxide (NOx) checked & controlled. This job is mainly done through a movable part called EGR Valve. 

The EGR Valve position sensor sends information related to the PCM related to the EGR Valve. When it sends information indicating a lower EGR Valve position than recommended, the PCM generates P0405. 

On the surface, it may sound like there could be something wrong with the EGR Valve position sensor – but it’s not. One way or another, the root cause is always (almost) a faulty EGR Valve. 

Symptoms Of Getting The P0405 Code On A 6.0

You’ll notice some symptoms while having the P0405 code on a 6.0L Powerstroke. Expect to have the error code if you’re getting the following symptoms: 

  1. Check Engine Light (CEL) is Activated 
  2. Rough Driving Experience 
  3. Engine Stall Issue 
  4. Disabled EGR system 

The Causing Factors Of The Error Code P0405

Though the root cause of the P0405 is a faulty EGR valve. Here are some other factors that might also cause the error code P0405: 

  1. Low Voltage From The EGR Valve Position Sensor 
  2. EGR Valve is Plugged or Clogged
  3. A Faulty PCM (Rare Case)

If the code is set due to a faulty PCM, expect to see other codes besides the P0405. 

How Serious Is Code P0405 On 6.0L Powerstroke 

Most likely, your EGR system will be disabled if you’re getting the error code P0405. Disabled or malfunctioning EGR won’t help with the NOx emission & may bring you legal troubles. 

Your CEL will remain illuminated until the code is fixed. In this way, you won’t know even if your engine is having other severe problems. That’s why it’s better to solve the code avoiding further complexity. 

How To Solve P0405 Error Code On 6.0L Powerstroke?

You can easily solve the P0405 code on your own if you’ve basic tool usage knowledge. Mainly you’ll be using these tools throughout your code solving journey: 

  • Electric Screwdriver
  • Crow Foot Pry Bar
  • Digital Volt/Ohm Meter
  • OBD-II Scanner

I hope you have these tools & you know the proper way to use them. So without further ado, let’s get started with the troubleshooting methods: 

Clean The EGR Valve

The EGR valve position makes carbon particles easy to get into. Over time, the EGR valve becomes clogged or plugged due to the heavy carbon & dust layers. 

As the valve malfunctions when it’s plugged, you might see the error code P0405. That’s why it’s better to clean the EGR valve first before replacing it.

Here’s how you can take out the EGR valve & clean it nicely:

  • Step 1: Open the hood & locate the EGR valve. 
  • Step 2: This valve is supported by two eight mm head screws. Unscrew them with an electric screwdriver. 
  • Step 3: Now, you’ll need a regular crowfoot pry bar to pull out the EGR valve. 

Lastly, reset the code with a scanner & check if the code returns.

If cleaning the EGR valve didn’t help to solve your code, follow the next troubleshooting method. 

Replace The EGR Valve

Most of the time, the error code P0405 refers to a faulty EGR valve & replacing is the only solution. If you’ve already tried to clean your valve & failed to solve the code, try replacing it. 

Here is how you can remove & replace the EGR valve with your basic household tools: 

  • Step 1: Open the hood & locate the EGR valve. 
  • Step 2: This valve is supported by two eight mm head screws. Unscrew them with an electric screwdriver. 
  • Step 3: Now, you’ll need a regular crowfoot pry bar to pull out the EGR valve. 
  • Step 4: Finally, try matching the old EGR valve with the new one & see if they match. 
  • Step 5: Replace the EGR valve with the new one & screw the two eight mm head bolts again. 
  • Step 6: Close the hood & you’re all set. 

After replacing the EGR valve, the DTC P0405 should be solved. Clean the code with a scanner & see if the code returns. 

Replace The PCM

If replacing the EGR valve couldn’t solve the code, suspect the PCM to be faulty. The EGR valve requires 5 volts of electricity from the PCM to function properly. Test the volt reference circuit & see if 5 volts is present.

If you see no voltage at all, the PCM is faulty. Consult an expert technician to check your vehicle for the last time before you replace the PCM. Later on, hand over the task to experts for a safer replacement.

How Much Does It Cost To Solve The Error Code P0405

The cost of solving the error code differs from truck to truck. Mainly you’ll be spending money on replacement parts like the EGR Valve & PCM. Here is the price chart of potential replacements:

  • The EGR Valve Costs Around $200
  • The PCM Costs Around $500
  • Electric Screwdriver Costs $120 to $150

If you’re getting all the work from an auto shop, add an extra $75 to $150 per hour labor fees too. 

Common Mistakes While Solving The P0405 Code

Several misdiagnoses may happen with the P0405 code. Try avoiding these common mistakes while solving the P0405 code: 

  • Thinking The Injectors Are Faulty 
  • Thinking The Turbocharger Is Faulty 

Additional Comments To Consider Regarding The P0405 Code

You can live without the EGR system. The problem is – some countries decided to make EGR usage a mandate. If you’re living in one of those countries, fix your EGR issues as soon as possible. 


I hope this article was informative enough about the P0405 code of the Ford 6.0 Powerstroke. Now you know how to identify & fix this code on your own.

Yes, this code is fixable by any individual until it requires replacing the PCM (which is very rare to happen). Consult an expert & he’ll take care of the faulty PCM issue.

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