P0257 Injection Pump Fuel Metering Control B Range Performance Injector

• OBD2 Code: P0257
• Description: Injection Pump Fuel Metering Control “B” Range/Performance (Injector)
• Definition: This code indicates that the fuel injection pump is not delivering the expected amount of fuel to the engine. The control module has detected a discrepancy in the performance or range of the fuel metering system, specifically related to injector circuit “B”. This can be due to mechanical issues with the pump, electrical problems in the circuit, or other related faults.

P0257 – Injection Pump Fuel Metering Control “B” Range/Performance (Injector Add)

Typical Severity: Moderate

Common Causes

P0257 – Injection Pump Fuel Metering Control “B” Range/Performance (Injector)

Common causes:

• Faulty fuel injector
• Clogged fuel injector
• Wiring issues in the fuel injector circuit
• Low fuel pressure
• Dirty or contaminated fuel system components

 

Common Misdiagnosis

OBD2 Code: P0257

Description: Injection Pump Fuel Metering Control “B” Range/Performance (Injector)

Common Misdiagnosis: Replacing the fuel injectors without checking for issues with the fuel pump or fuel pressure regulator.

 

Common Diagnostic Steps

OBD2 Code: P0257

Description: Injection Pump Fuel Metering Control “B” Range/Performance (Injector)

• Check for any additional trouble codes that may be present.
• Inspect the fuel injectors and injection pump for signs of damage or wear.
• Test the fuel pressure to ensure it is within the manufacturer’s specifications.
• Examine the wiring and connectors related to the fuel metering control circuit for any signs of corrosion, damage, or disconnection.
• Use a scan tool to monitor live data from the engine control module (ECM) to check for irregularities in fuel delivery.
• Perform a visual inspection of vacuum lines and hoses connected to the injection system for leaks or blockages.
• If applicable, test the operation of any associated sensors such as mass air flow sensor or manifold absolute pressure sensor that could affect fuel metering.
• Clear all codes after repairs are made and perform a road test to ensure proper operation and that no codes return.