P0260

Injection Pump Fuel Metering Control B Intermittent (Cam/Rotor/Injector)

P0260 is a generic OBD-II powertrain diagnostic trouble code: Injection Pump Fuel Metering Control B Intermittent (Cam/Rotor/Injector). It is logged by the engine control unit when the fuel/inj monitor detects that a specific fault threshold has been exceeded — typically resulting in the malfunction-indicator lamp (MIL / check-engine light) being illuminated.

Code
P0260
Group
Powertrain
System
Fuel/Inj
Severity
Warning (MIL on, possible limp mode)
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What P0260 means

P0260 is set when the ECM/PCM detects an unstable or intermittent electrical signal from the fuel metering control circuit designated as "B" on the injection pump. Unlike the steady low or high faults of related codes, the intermittent nature means the signal drops in and out — the valve or its wiring momentarily loses integrity, causing the ECM to lose accurate control over fuel delivery quantity. This code belongs to the P0256–P0260 group covering injection pump fuel metering control circuits A through B.

The metering control valve (also called a fuel quantity actuator or fuel rail pressure solenoid depending on architecture) regulates how much high-pressure fuel enters the common rail or pump discharge. When its circuit becomes intermittent, the ECM cannot maintain a precise fuel mass command, resulting in fluctuating rail pressure and erratic combustion. Because the fault is transient, symptoms may disappear when the connection stabilises, making diagnosis more challenging than a hard open or short.

This code is predominantly found on diesel-fuelled vehicles — including common Mercedes-Benz CDI, Volkswagen TDI, and other European diesel platforms — that use electronically governed high-pressure injection pumps. Electrical connector corrosion is the single most common root cause; outright pump or solenoid failure is less frequent.

Common causes

Most-frequently reported root causes when P0260 is logged.

  • 1
    Intermittent open or high-resistance connection in the metering control "B" circuit wiring or connector
  • 2
    Corroded, loose, or damaged electrical connector at the fuel quantity actuator or metering solenoid
  • 3
    Chafed or heat-damaged wiring harness causing an intermittent short to ground or open
  • 4
    Failing fuel metering solenoid ("B") with an internal intermittent winding fault
  • 5
    Defective high-pressure injection pump with worn or sticky metering valve mechanics
  • 6
    Failed or intermittent fuel rail pressure (FRP) sensor providing corrupted feedback to the ECM
  • 7
    PCM/ECM driver circuit degradation causing intermittent loss of control signal (rare)

Symptoms drivers notice

Check engine light illuminated (MIL on), sometimes flickering intermittently
Intermittent rough running, hesitation, or surging under load
Engine may run lean or rich depending on the position the valve sticks in
Reduced engine power or activation of power-limiting limp mode during fault events
Hard cold start or extended cranking when the fault occurs at start-up
Intermittent stalling or rough idle that clears spontaneously

How to diagnose P0260

A typical diagnostic flow when this code is present.

  1. 1
    Connect a scan tool, record all stored DTCs and freeze-frame data, and note whether companion codes P0256–P0259 are also present.
  2. 2
    Inspect the metering solenoid wiring harness and connector for corrosion, bent pins, chafing, or heat damage near the injection pump.
  3. 3
    Disconnect the connector, clean the terminals with electrical contact cleaner, reconnect firmly, clear codes, and road-test to check for recurrence.
  4. 4
    With the ignition on and engine off, measure supply voltage and ground integrity at the solenoid connector with a digital multimeter against manufacturer specifications.
  5. 5
    Check the signal wire voltage to the solenoid; measure resistance of the solenoid coil and compare to specification (typically 3–12 Ω for a metering solenoid).
  6. 6
    Monitor live fuel rail pressure data on a scan tool during a test drive to identify pressure instability that correlates with the intermittent fault event.
  7. 7
    If wiring and connections test good, replace the fuel quantity actuator / metering solenoid; suspect the injection pump only if the solenoid replacement does not resolve the fault.

Related powertrain codes

Frequently asked questions

Why does P0260 appear and disappear without any obvious trigger?

The 'intermittent' designation means the fault exists but is not constant. Connector corrosion or a hairline crack in the wiring creates a resistance that only opens under heat, vibration, or mechanical flex. Cleaning the connector or replacing a damaged section of harness typically resolves the intermittent behaviour.

Is P0260 dangerous to drive with?

It can be. When the metering fault occurs the ECM may temporarily lose fuel quantity control, which can cause a sudden loss of power at speed. If the engine enters limp mode while driving, performance is restricted but the vehicle remains drivable to a workshop. Prolonged neglect risks uncontrolled fuel delivery events that can damage the injectors or turbocharger.

What is the difference between P0260 and P0257?

P0257 and P0258 indicate a steady low or high condition in the metering 'B' circuit, suggesting a hard electrical fault. P0260 indicates the same circuit but with an intermittent signal — the fault comes and goes, making it a wiring integrity or connection issue rather than a straightforward component failure.

Can a failing fuel rail pressure sensor cause P0260?

Yes. The ECM uses FRP sensor feedback to regulate the metering valve. If the FRP sensor delivers an unstable signal, the ECM may interpret the resulting control loop instability as an intermittent metering circuit fault and log P0260 alongside FRP-related codes. Always check for companion FRP codes before condemning the metering valve.

Disabling P0260 in software

RaceTune can permanently disable P0260 — and any other OBD-II diagnostic trouble code — on every ECU family we support. The monitor is disabled inside the ECU itself, so the fault stops being logged: the warning light stays off and the engine never enters limp mode for this code. The change is tied to your exact software version.

Permanent
The monitor is disabled in the ECU itself — not just cleared. It cannot return.
Tailored to your file
Each patch is matched to your specific software version — never a one-size-fits-all file.
Reversible
The original file is always preserved. Reflash the stock to return the ECU to factory state.

Software modifications affect emissions compliance and are not road-legal in many jurisdictions. RaceTune service files are intended for motorsport, off-road, and export use.

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