P0256 OBD-II Trouble Code: Injection Pump Fuel Metering Control "B" Malfunction (Cam/Rotor/Injector)

Our certified mechanics come to you · Get a fair and transparent estimate upfront

Red-stars EXCELLENT RATING ON

Cost of diagnosing the P0256 code

P0256 is a diagnostic trouble code (DTC) for "Injection Pump Fuel Metering Control "B" Malfunction (Cam/Rotor/Injector)". This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation. Our certified mobile mechanics can come to your home or office to perform the Check Engine Light diagnostic. Once we are able to diagnose the problem, you will be provided with an upfront quote for the recommended fix and receive $20.00 off as a credit towards the repair. All our repairs are backed by our 12-month / 12,000-mile warranty.

Cars Estimate Credit towards follow-up repair Earliest Availability
Ford$20.00
Toyota$20.00
BMW$20.00
SCHEDULE P0256 DIAGNOSTIC Get a fair and transparent estimate upfront

P0256 code definition

The P0256 Trouble Code indicates injection pump fuel metering control “B” malfunction (cam/rotor/injector).

What the P0256 code means

When this code appears, it means that the powertrain control module has found that the signal voltage to the electronic fuel control actuator and the signal returning from the fuel metering control sensor are incorrect. This code is only for diesel-powered vehicles, and it should never appear in non-diesel vehicles. If it does, it will mean there is an issue with the powertrain control module.

What causes the P0256 code?

Several different things could cause the P0256 code to appear, including the following:

  • Dirty fuel filter
  • Clogged fuel filter
  • Defective fuel pump
  • Shorted or open circuits
  • Shorted or open electrical connectors
  • Faulty fuel control actuator driver in the powertrain control module

What are the symptoms of the P0256 code?

The symptoms of the P0256 code can vary substantially. In some instances, the driver might only have the code stored in the vehicle and have to contend with a service engine soon light. However, it could be more problematic in other cases. Sometimes, there will be an excessive amount of smoke coming from the exhaust. There could also be engine misfires and hesitation when you are trying to accelerate. Other times, the vehicle might be difficult to start, or it might not start at all.

How does a mechanic diagnose the P0256 code?

The mechanic needs to connect to the vehicle’s onboard computer. Most vehicles over the last few decades have these computers inside them. The mechanic can hook up their OBD-II scanner to the computer to gather data about the codes and to help diagnose the issues with the vehicle. They will then reset the code and test the vehicle. They want to see if the code returns. If the code comes back, it means that it was not triggered by mistake, and then they can continue to look for the root cause of the problem.

Common mistakes when diagnosing the P0256 code

The most common mistake when diagnosing the P0256 code and trying to repair the vehicle is believing that the injector pump or the injectors are the problem. Most of the time, these will not need to be replaced. Instead, it is usually a problem with the fuel filter, or issues with the wiring.

How serious is the P0256 code?

While you might not always have many symptoms when you have the P0256 code, that doesn’t mean that you should drive your vehicle around in that condition. It still needs to be taken to a mechanic who can go over the vehicle and make all of the needed repairs. In addition, there is also the chance that the vehicle could start to run rough, or that it might not start at all.

What repairs can fix the P0256 code?

The following are some of the repairs and fixes that the mechanic could make to fix the P0256 code:

  • Check the vehicle using the OBD-II device
  • Reset the code and test the vehicle to see if it comes back
  • Check the electrical connections for corrosion and other issues
  • Replace the fuel filter
  • Replace the fuel pump
  • Replace the fuel control actuator driver in the powertrain control module

Additional comments for consideration regarding the P0256 code

Do not neglect your vehicle. Many drivers will have codes show up in their vehicle, but they opt not to do anything about them because they haven’t noticed a problem with the way their vehicle runs. This could be a mistake. The P0256 code might not have any effects other than an illuminated Check Engine Light. However, you don’t want to run the risk that one day you will head outside and find that your vehicle no longer starts or that you now have other codes and issues to contend with.

Need help with a P0256 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

trouble codes
P0256
Check Engine Light

No more waiting rooms! Our mechanics will come to you to diagnose and fix the P0256 code.

SCHEDULE P0256 DIAGNOSTIC
Get a $20 credit for the follow-up repair

Recent Check Engine Light is on Inspection reviews

Excellent Rating


YourMechanic Check Engine Light is on Inspection Service

Average Rating

4.8/5

Number of Reviews

5,626

Rating Summary
5,199
206
50
34
137
5,199
206
50
34
137

Robert

11 years of experience
104 reviews
Robert
11 years of experience
Nissan Quest - Check Engine Light is on - Alexandria, Virginia
Punctual. Knowledgeable. Professional. Empathic, went the extra mile to explain in lay words the mechanical jargon. Excellent manners and customer service oriented. Client’s best interest and safety was always his top priority. From now on your company has in me a client for life. Thanks Robert!!!! 

Chris

21 years of experience
1861 reviews
Chris
21 years of experience
Mercedes-Benz E320 - Check Engine Light is on - Ladera Ranch, California
Chris was friendly, professional and knowledgeable. He got to the point of my concerns, explained what he was finding on his system and gave me his recommendations. I fully appreciate him taking the time to explain everything and a bit of history on my vehicle. Thanks again Chris.

Michael

15 years of experience
574 reviews
Michael
15 years of experience
Hyundai Accent - Check Engine Light is on - Marietta, Georgia
I had a great experience with Michael. He's extremely professional, friendly, and understands his craft. Highly recommended.

Chris

15 years of experience
274 reviews
Chris
15 years of experience
Dodge Durango - Check Engine Light is on - San Diego, California
Showed up early, was a friendly dude, kept me informed via text, did clean work and finished early. Would hire again.


More related articles

P0774 OBD-II Trouble Code: Shift Solenoid E Intermittent
P0774 means the PCM registered a problem in shift solenoid E, caused by low ATF level, failed shift solenoid, or blocked transmission passages.
B1924 OBD-II Trouble Code: Air Bag Internal Diagnostic Monitor Fault or System Disarm Fault
B1924 means there is a problem with the air bag system circuit, likely due to a defective electrical component or faulty diagnostic monitor.
P0788 OBD-II Trouble Code: Shift/Timing Solenoid High
P0788 means that the ECM has detected a high voltage from the timing solenoid valve (TCM) terminal due to low or dirty fluid, or shorted solenoid.

Related questions

Check Engine and VSA light coming on

Hi there, VSA stands for Vehicle Stability Assist and is Honda's computer system that helps ensure the tires have traction to help keep you on the road. When both the check engine light and the VSA light are illuminated it...

The Check Engine Light came on after washing my Durango

It sound like you got water into some of the electrical connections from the water that is sprayed sideways and from the bottom of some of these car washes. Also, your car was running, which could cause the water to...

Check Engine light code P0430

Your vehicle has groups of sensors that take readings and report back to the engine computer to make adjustments, or report an error; in this case, we're dealing with oxygen and/or air/fuel-ratio sensors. The code P0430 indicates a failure...

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1 (855) 347-2779 · hi@yourmechanic.com