Code Definition

P0256 — Injection Pump Fuel Metering Control Circuit B Malfunction

System: Powertrain  |  Type: Generic (OBD-II Standard)  |  Make: Generic

About P0256

P0256 is a generic (obd-ii standard) powertrain diagnostic trouble code. It belongs to the P-prefix family of codes, which covers engine, transmission, emissions, or fuel-system faults.

When P0256 is stored, the module has detected an electrical-circuit fault in the wiring, connector, or driver associated with the named component.

Scanning & clearing: A generic OBD-II scan tool will usually read and clear powertrain (P) codes. For live data, freeze-frame capture, and bi-directional tests you may need a more capable scan tool that supports the vehicle's ECM protocol.

Because P0256 is a generic OBD-II code, its base definition is shared across manufacturers. The specific diagnostic steps, reference values, and repair procedures can vary by vehicle, and the TaT Diagnostic Assistant includes verified procedures submitted by working technicians.

Code Information

The P0256 fault code is set when the powertrain control module (PCM) detects a malfunction in the fuel metering control circuit labelled as 'Control B' of the injection pump. This indicates an issue with the circuit or component responsible for managing fuel delivery to maintain proper engine operation. The fault may involve electrical or mechanical issues within the system.

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