Fuel and air

P0254 — Injection Pump Fuel Metering Control A Circuit High

Severity: medium Drive with care, to a shop

What P0254 means

On a diesel, the engine computer controls how much fuel the injection pump delivers through a metering actuator (solenoid or valve) in circuit A. P0254 sets when the voltage or signal in that circuit is higher than expected. Typical causes are a short to voltage, a bad actuator, a failing pump, or a faulty driver in the computer.

Symptoms

  • Check engine light on
  • Loss of power or hesitation when accelerating
  • Rough idle
  • Engine stalling
  • Hard starting
  • Poor fuel economy
  • Reduced-power (limp) mode

Possible causes

  1. Wiring shorted to voltage or damaged in the metering circuit
  2. Corroded or damaged connectors at the pump or ECU
  3. Faulty fuel metering actuator (solenoid or valve) on the pump
  4. Internal injection pump fault (cam, rotor)
  5. Failed output driver in the ECU
  6. Outdated ECU software (uncommon)

How to diagnose

  1. Read codes and freeze-frame data, clear the code and see if it returns
  2. Inspect the pump harness and connectors for chafing, oil, corrosion and loose pins
  3. Test the circuit for short to voltage, short to ground and open circuit with a multimeter and wiring diagram
  4. Measure the actuator resistance and compare to the manufacturer's spec
  5. Check supply voltage and the control signal at the pump connector
  6. Check fuel pressure and the filter, and look for air leaks in the fuel supply
  7. Compare commanded and actual fuel metering values on a scan tool
  8. If wiring and actuator are good, test the ECU and the pump itself

Common fixes

  • Repair the wiring or replace damaged connectors
  • Replace the fuel metering actuator
  • Update or reflash ECU software if available
  • Repair or replace the injection pump
  • Replace the ECU once it is confirmed faulty

Questions and answers

What does P0254 mean?

The ECU detected a high signal in the injection pump fuel metering control A circuit. Wiring, connectors and the metering actuator are the most common culprits.

Can I drive with P0254?

Only for a short trip to a shop. The engine may lose power or stall, so get it diagnosed soon.

Will clearing the P0254 code fix it?

Clearing only turns off the light. If the cause is still there, the code will return, so check the wiring, connectors and pump actuator first.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.