Error code

OBD2 P0256

OBD2P0256
Diagnostic Trouble Code· Standard OBD-II fault code read from the vehicle's onboard diagnostics.

What it means

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

Severity

highDrive with caution; potential for engine malfunction and increased emissions.

Summary

P0256 indicates an issue with the injection pump fuel metering control 'B' (cam/rotor/injector) circuit malfunction in diesel vehicles. This code suggests that there is a discrepancy between expected and actual fuel delivery.

Symptoms

  • Illuminated warning light
  • Increased fuel consumption
  • Hard starting condition
  • Misfires, loss of power, or hesitation upon acceleration
  • Excessive smoke from the tailpipe

Common Causes

  • Damaged wiring and connectors
  • Clogged fuel filter
  • Defective Fuel Control Actuator
  • Faulty Fuel Rack Position sensor
  • Defective injection pump (rare)
  • Failed or failing fuel control driver in the PCM (very rare)

Diagnosis

  1. Record freeze frame data
  2. Inspect wiring and connectors for damage
  3. Test electrical circuits for proper voltage, resistance, and continuity
  4. Check Fuel Rack Position sensor and Fuel Control Actuator

Fixes

  • Repair or replace damaged wiring and connectors
  • Replace faulty Fuel Control Actuator or Fuel Rack Position sensor

FAQ

What should I do if the code persists after repairs?

If P0256 returns, it may indicate an intermittent fault. Repeat electrical tests to find and repair the issue or seek professional help.

Can this code cause damage to other components like the catalytic converter?

Yes, in extreme cases, unresolved issues can lead to damage of the catalytic converter or DPF (Diesel Particulate Filter).

View source

Not affiliated with OBD2. Answer summarized from the manufacturer's manual linked above; consult that source for the authoritative procedure.

More OBD2 codes

All OBD2 codes →Search more codes →