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SPN 1347 — Fuel Delivery Pump Assembly #1

Safe to driveTo the nearest safe stop

Updated: 2026-11-10

J1939 code SPN 1347. Below — how the fault is worded at the factory by Cummins ISB, DAF, Dongfeng, Isuzu and Renault Trucks, and what the second half of the code (FMI) means in the standard.

How to check it yourself

The pump unit — the fuel metering valve on the Common Rail high-pressure pump. The ECU uses it to decide how much fuel the pump delivers to the rail. This code is about this valve's circuit, or about pressure it cannot hold.

What it should read

Metering valve winding resistanceusually a few ohms — per the factory data
Rail pressuresee SPN 157

Check order

  1. FMI 3, 4: unplug the connector on the pump, inspect it, and measure the valve winding.
  2. FMI 0, 7 (pressure will not hold): fuel first — filters, transfer pump, air. The metering valve sticks from dirt and water in the fuel.
  3. Check the leak-off from the injectors and the rail's relief valve — they draw the pressure down, and the ECU blames the pump.
  4. On many systems the valve is replaced separately from the pump — do not rush to replace the pump.

Common causes — from most to least frequent

  1. Dirt or water in the fuel — the metering valve sticks.
  2. Connector on the pump.
  3. Pressure leak through the injectors or the relief valve.
  4. Worn high-pressure pump.

Cummins ISBDAFDongfengIsuzuRenault Trucks

Cummins ISB 6.7 engine

FMI 3Fuel pump pressurizing assembly circuit voltage high
FMI 4Fuel pump pressurizing assembly circuit voltage low

DAF

FMI 3Fuel pump control valve B334 short to power supply/open circuit at ECU pin A10
FMI 4Fuel pump control valve B334 short to ground at ECU pin A10

Dongfeng

FMI 3Open circuit of the fuel metering solenoid valve
FMI 4Short circuit of the fuel metering solenoid valve
FMI 7Unbalanced fuel supply between engine cylinders

Isuzu

FMI 0SCV drive system open circuit, +B short or ground short (P0090)

Renault Trucks

FMI 4Pump 1 solenoid valve, open circuit or short. Repair: Check the solenoid valve and the wiring (A 9, A 20).

What FMI means in J1939

SPN 1347 FMI 01347/0 · 1347.0data above normal range (most severe level)
SPN 1347 FMI 31347/3 · 1347.3voltage above normal or shorted high
SPN 1347 FMI 41347/4 · 1347.4voltage below normal or shorted to ground
SPN 1347 FMI 71347/7 · 1347.7mechanical system not responding

Can I keep driving

Safe to drive. Below — how much time you have and what happens if you keep going.

What happens if you keep driving

Time you have: To the nearest safe stop

Fuel is not arriving in the right amount or at the right pressure. It shows up first on climbs and under load.

You will most likely stall out on the road, and may not restart on the shoulder. A clogged filter or water in the tank you can nurse to a shop; a failing injection pump you cannot.

This is an electrical fault: an open, a short or a bad contact in the sensor circuit. The value it measures is most likely fine. You can drive. But until the circuit is repaired this system runs blind and cannot warn you about a real failure.

What to check on the spot

Check the fuel filter and water trap, drain the water. In cold weather, suspect fuel waxing.

Nearby: fuel

Makes with this code

DongfengDAFRenault TrucksIsuzuCummins ISB

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