AutoCodes – Generic – P0255

P0255 Code - Injection Pump Fuel Metering Control 'A' Intermittent

Quick Answer

This fault code is stored in the Engine Control Module (ECM) when the system cannot correctly control the fuel pressure. Common causes include Faulty Fuel Pump, Fuel Pump harness is open or shorted, Fuel Pump circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: P0255 indicates Injection Pump Fuel Metering Control 'A' Intermittent.
Common causes: Common causes include Faulty Fuel Pump, Fuel Pump harness is open or shorted, Fuel Pump circuit poor electrical connection.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 18,426

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jul 09, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
Comments
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Code P0255 Description

This fault code is stored in the Engine Control Module (ECM) when the system cannot correctly control the fuel pressure. The engine control module uses feedback from the fuel pressure sensor to monitor fuel pressure. The fuel inlet metering valve circuit integrity is also monitored to ensure the circuit and component are functioning correctly.
Normally manufacturers will support data parameters for actual and desired fuel pressure.
A number of issues may cause this fault code to be set such as a faulty fuel rail pressure sensor, a mechanical fault with a fuel inlet metering valve could cause the valve to become stuck. An electrical fault such as an open circuit in the fuel inlet metering valve on a system with a normally closed valve will also cause this situation. A short circuit on the control wire of a normally open fuel pressure regulator will also cause this fault.
A fault in the fuel injector return system will cause the fuel pressure to be lower than expected. This causes fuel from the high-pressure circuit to be leaked back to the low-pressure circuit. A faulty maximum pressure relief valve will also cause this situation.
The high-pressure pump should also be tested to ensure it is capable of delivering the required volume of fuel.

OBDII Code P0255 - Injection Pump Fuel Metering Control 'A' Intermittent - AutoCodes.com — P0255 Code - Injection Pump Fuel Metering Control 'A' Intermittent

What does this mean?

What are the Possible Causes of the DTC P0255?

Faulty Fuel Pump
Fuel Pump harness is open or shorted
Fuel Pump circuit poor electrical connection
Faulty Engine Control Module (ECM)

How to Fix the DTC P0255?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0255 code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the P0255 code?

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Information for Specific Makes

P0255 Mercedes-Benz — Injection Pump Fuel Metering Control 'A' Intermittent

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.