SPN 1347 - FMI 7 (Fault Code 281)

SPN 1347 - FMI 7 (Fault Code 281)
SPN1347 FMI7

High Pressure Pump

Fault Code: 281
PID(P), SID(S): S126
SPN: 1347
FMI: 7

REASON: Fuel Pump Pressurizing Assembly 1 - Mechanical System Not Responding Properly or Out of Adjustment.

EFFECT: Engine will NOT run or possible low power.

Circuit Description:
The fuel pump contains two barrel and plunger assemblies; each barrel and plunger assembly utilizes an inlet and outlet check valve. Fuel at gear pump pressure is metered through the fuel pump actuator and unseats one of the two inlet check valves as the fuel at gear pump pressure enters the pumping chamber. As the pumping plunger begins its upward motion, the pressure in the pumping chamber increases rapidly and the inlet check valve is closed. As pressure reaches accumulator pressure, the outlet check valve is opened. As the plunger travels upward, fuel exits past the outlet check valve and pressurizes the fuel rail.

Component Location:
The fuel pump is located on the backside of the gear housing. The barrel and plunger and check valve assemblies are part of the fuel pump head sub-assembly.

Conditions for Running the Diagnostics:
This diagnostic runs continuously when the engine is running.

Conditions for Setting the Fault Codes:
This fault code is set active when a pumping imbalance is detected between the two high-pressure plungers inside the fuel pump.

Action Taken When the Fault Code is Active:
• The ECM illuminates the amber CHECK ENGINE light immediately when the diagnostic runs and fails.

Conditions for Clearing the Fault Code:
When the ECM detects that the pumping imbalance has been corrected, the fault code is set inactive.

Shop Talk:

  • Verify the electronic control module (ECM) calibration is correct. Check the calibration revision history found on QuickServe™ Online for applicable fixes to the calibration stored in the ECM. If necessary, calibrate the ECM.
  • Fault Code 281 will most likely come active while operating at a steady state loaded condition. At this condition, commanded fuel pressures are highest and the pump's pressure balance is affected the most.
  • If a high pressure seal has failed, pump head drain flow will be excessive. If seal damage has progressed far enough, the engine may not start because of an inability to develop fuel rail pressure.
  • If the engine will not start, there are two indications that the pump head has malfunctioned:

-The drain flow will be excessive. This can be measured while cranking the engine.
-The pumping plungers are broken or mechanically stuck. This can be checked by visual inspection.

  • If the engine oil level is rising due to the oil and Fault Code 281 is active, the pump head has malfunctioned and must be replaced.

Read More:
SPN 1347 - FMI 3 (Fault Code 272)
SPN 1347 - FMI 4 (Fault Code 271)


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1 Response to "SPN 1347 - FMI 7 (Fault Code 281)"

  1. Bon soir
    Le démarrage du moteur a été bloqué par un code erreur spn1347 fait tourner le moteur a 1150tr/min