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P0259 Code – What Does It Mean & How To Fix It

This is one of the most frequent OBD2 trouble codes. Read the full article below to know what it means, how to fix it, and what other codes may show related to it.


The P0259 DTC code is a diagnostic trouble code that pertains to the injection pump fuel metering control ‘B’ circuit high. In simple terms, this indicates that the “B” circuit of fuel metering controls on your vehicle’s injection pump is out of order and may result in problems with gas delivery or engine performance.


If the code P0259 is detected on your vehicle’s onboard computer, this means that an electrical fault exists in the “B” circuit of a fuel metering device. This defect may lead to incorrect combustion and low engine efficiency, which could affect the precise control of fuel delivery into the engine.


It’s critical to pinpoint probable underlying causes for the P0259 DTC code to handle it successfully. These may consist of:

  • Faulty Fuel Injection Pump: The P0259 code may be set off by a faulty fuel injection pump that is causing electrical problems in the ‘B’ circuit.
  • Problems with the wiring or connections: The ‘B’ circuit’s wires, connectors, or terminals that are damaged or corroded may cause improper electrical signals.
  • Fuel metering control valve issue: A faulty fuel metering control valve might damage the ‘B’ circuit and activate the code.
  • Faulty PCM (Powertrain Control Module): In rare cases, a malfunctioning PCM can generate erroneous signals, causing the P0259 code.


  • You can respond quickly by recognizing the symptoms linked to the P0259 code. Typical signs could include:
  • Reduced Engine Performance: The power and responsiveness of your engine may noticeably decline.
  • Reduced gasoline Efficiency: Because of poor combustion, the engine may use more gasoline than usual.
  • Rough idle: When the code is active, your car may idle rough or possibly stall.


To properly treat the P0259 code, an accurate diagnosis is necessary. Here is the normal procedure:

  • Scanner for OBD-II: To obtain the P0259 code and any associated issue codes, use an OBD-II scanner.
  • Visual Inspection: Check the ‘B’ circuit’s wire, connections, and terminals for corrosion or damage that is readily apparent.
  • Electrical Testing: Run electrical tests to evaluate the ‘B’ circuit for voltage, resistance, and continuity.
  • Inspection of the Fuel Injection Pump: If required, check the Fuel Injection Pump for any flaws or issues.

Common mistakes

  • Avoid making the following mistakes while dealing with the P0259 error:
  • Ignoring the Code: Ignoring a check engine light and any related codes may cause more serious and expensive problems in the future.
  • Insufficient diagnostic: Failure to conduct a thorough diagnostic may lead to pointless repairs.
  • DIY Without Knowledge: Attempting to repair the problem without the required knowledge might result in more harm.

How serious is this?

The intensity of the code P0259 shall be determined based on an underlying issue and its scope. Unresolved problems may appear to be merely an inconvenience, but they could lead to more extensive engine issues and a decrease in fuel efficiency.

What repairs can fix the codeS?

repair manuals

The following repair options are frequently used to address the P0259 error code:

  • Fuel Metering Control Valve Replacement: If the fuel metering control valve is broken, it has to be replaced.
  • Repair wire or Connectors: In the ‘B’ circuit, repair or replace any corroded, damaged, or broken wire, connectors, or terminals.
  • PCM Replacement: If the PCM is faulty, it may occasionally need to be replaced or reprogrammed.

Related codes

Several related codes might accompany the P0259 DTC, including:

  • P0256: Injection Pump Fuel Metering Control ‘B’ Range/Performance
  • P0257: Injection Pump Fuel Metering Control ‘B’ Circuit Low
  • P0258: Injection Pump Fuel Metering Control ‘B’ Circuit High


In conclusion, the P0259 DTC code is a diagnostic trouble code that signals an issue with the ‘B’ circuit of the fuel metering control within your vehicle’s injection pump. While it may initially appear as a minor problem, addressing it promptly is essential to prevent more significant engine issues and reduced fuel efficiency.

Proper diagnosis and repair by a qualified mechanic are crucial to restoring your vehicle’s optimal performance. If you encounter the P0259 code, taking action swiftly will help ensure your car runs smoothly and efficiently.

P0259 Code – What Does It Mean & How To Fix It