P0255 — Injection Pump Fuel Metering Control A Intermittent
P0255 means the ECM saw an intermittent fault in the injection pump fuel metering control A circuit, the actuator that regulates fuel delivered to the injection pump on most diesel systems. The signal or current dropped out or spiked briefly rather than staying failed. OEMs apply this code to different metering devices, but it almost always points to a connection or wiring issue rather than a steady component failure.
What this means for truckers
Service within a few days on a Cummins X15, Detroit DD15, PACCAR MX-13. Performance is likely degraded. Continuing to drive without service risks additional component damage.
Before you replace parts — try this first
P0255 on the Fuel system is most often loose, corroded or fretted terminals at the metering valve or ecm connector — not a dead part. On commercial diesels especially, work these in order before spending money on parts:
- Confirm the symptoms. Match what your truck is doing to the Symptoms section below. If the code is set but the symptoms are not there, clear the code and re-test after a drive cycle — it may not return.
- Clean and dry the sensor connector. Water, road salt, or oil seeping into a connector is the #1 fake sensor failure. Disconnect, look for green corrosion or moisture, spray with electrical contact cleaner, dry, reseat. Many faults clear here for $0.
- Inspect the wiring harness. Trace the wire from the sensor toward the ECM — look for chafing against the engine block, melted insulation near the turbo or exhaust, or pinch points where a clamp has rubbed through.
- Test the sensor before swapping it. Most Common Causes (below) list the expected voltage or resistance range — a $20 multimeter saves a $300 sensor swap that does not fix the problem.
- Only then, replace the part. Use the OEM or a tier-1 aftermarket. Cheap sensors throw the same code in two weeks.
Symptoms
Symptoms come and go: occasional stumble, momentary power loss, surging, intermittent hard start or brief stalling, often triggered by vibration, bumps or engine heat. The check-engine light may set and clear, and some engines log a temporary derate.
Common causes
- CommonLoose, corroded or fretted terminals at the metering valve or ECM connector ($100–$400)
- CommonHarness chafing against brackets, the pump or engine block causing intermittent contact ($150–$600)
- OccasionalMetering valve coil with an internal intermittent open that worsens when hot ($350–$1200)
- RarePoor ECM power or ground causing driver dropouts ($100–$500)
How to fix
Affects most
No specific vehicle pattern found in our complaint database. This code can appear on any vehicle that supports OBD-II diagnostics.
Related
- → Browse all DTC trouble codes
- → Decode a VIN to check codes for your truck
- → Owner-operator maintenance guides
- → P0200 — Injector Circuit Malfunction
- → P0201 — Injector Circuit Malfunction - Cylinder 1
- → P0202 — Injector Circuit Malfunction - Cylinder 2
- → P0203 — Injector Circuit Malfunction - Cylinder 3
- → P0204 — Injector Circuit Malfunction - Cylinder 4