P0255 critical

Injection Pump Fuel Metering Control A Intermittent (Diesel)

The P0255 code means the vehicle's onboard diagnostic system has detected: Injection Pump Fuel Metering Control A Intermittent (Diesel). This is a critical severity code.

My Garage →
Keep driving?
No -- stop driving
DIY difficulty
hard
Estimated cost
$200 - $800 (parts and labor)
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Common Symptoms

  • Check Engine Light on
  • Engine surges or hunts at idle
  • Intermittent power loss
  • Fuel rail pressure fluctuates erratically

Probable Causes (Ranked by Likelihood)

  • Loose connector at fuel metering valve Very High
  • Intermittent wire break in metering valve circuit High
  • Failing metering valve with intermittent coil Moderate
  • Fuel contamination causing sticking valve Low

Step-by-Step Diagnostic Procedure

  1. Monitor fuel rail pressure and metering valve duty cycle on scan tool. Look for erratic fluctuations.

  2. Wiggle test on metering valve connector while monitoring. Signal dropout confirms connector fault.

  3. Check wiring at vibration and heat stress points.

  4. Inspect fuel quality and filter condition.

Frequently Asked Questions

Why does the engine surge with P0255?

An intermittent metering valve connection causes fuel delivery to fluctuate, making the engine speed rise and fall as fuel pressure changes.

Can bad fuel cause P0255?

Yes, contaminated fuel with water or debris can cause the metering valve to stick intermittently, triggering this code.

Is P0255 an emergency?

Yes, intermittent fuel metering can cause dangerous pressure spikes. Have the vehicle towed for repair.

Sources

This page is built from documented references. Verify against your own service info before repair work.

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