New Holland WorkMaster 50 Service Manual page 890

DTC 26F-04-The minimum rail pressure value necessary to allow
fuel injection has not been reached
Control Module : ECU
NOTE: If the Pressure Relief Valve (PRV) is replaced, it is necessary to perform the Replacement of the Rail Pressure
Relief Valve (PRV) - Reset ECU Data with the Electronic Service Tool (EST) before you return the machine to service.
See Common rail Relief valve - Configure - Reset ECU data (10.218), if necessary.
NOTE: If the rail pressure sensor B-9004 is replaced, it is necessary to perform the Replacement of the Rail Pressure
sensor - Reset ECU Data with the Electronic Service Tool (EST) before you return the machine to service. See
Common rail pressure sensor - Configure - Reset ECU data (Rail pressure sensor) (55.010), if necessary.
Context:
The Engine Control Unit (ECU) A-9000 monitors fuel rail pressure. If the ECU A-9000 determines that fuel rail pressure
is less than 130.0 bar (1885.0 psi) or below a limit value from an ECU A-9000 calculated curve, this fault will occur.
Other active faults may have caused this fault to occur. For more information regarding fuel system troubleshooting,
see Fuel injection system - Troubleshooting (10.218).
Cause:
The ECU A-9000 has determined that fuel rail pressure is too low to continue engine operation.
Possible failure modes:
1. Faulty fuel metering unit Y-9000, stuck closed or internal failure.
2. Faulty high pressure pump, low efficiency.
3. Faulty charge gear pump, low efficiency.
4. Faulty fuel filters, clogged.
5. Faulty fuel lines, leakage or blockage.
6. Faulty electric fuel pump (if equipped).
7. Faulty fuel injectors, internal leakage or stuck open.
8. Faulty Pressure Relief Valve (PRV), leakage.
9. Faulty rail pressure sensor B-9004 drifted signal or leaking.
10. Faulty ECU A-9000, software.
Electrical systems - FAULT CODES
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