New Holland WorkMaster 50 Service Manual page 772

DTC 155-03-Fuel rail pressure has exceeded maximum limit
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 using the rail pressure sensor B-9004. If the ECU
A-9000 determines that the measured rail pressure is greater than desired by more than a dependent engine speed
value, this fault will occur. For more information regarding fuel system troubleshooting, see Fuel injection system -
Troubleshooting (10.218).
Cause:
The ECU A-9000 has determined that the measured rail pressure is greater than desired by more than a dependent
engine speed value.
Possible failure modes:
1. Faulty fuel metering unit Y-9000 wiring, broken or poor connections.
2. Faulty fuel metering unit Y-9000, stuck open or internal failure.
3. Faulty fuel back-flow lines, blocked or damaged.
4. Faulty Pressure Relief Valve (PRV), stuck closed or mechanically unable to open.
5. Faulty high pressure pump, zero delivery throttle valve clogged.
6. Faulty rail pressure sensor B-9004, drifted signal.
7. Faulty ECU A-9000, software.
Solution:
1. Verify fault is present and active.
Use the Electronic Service Tool (EST) to check the status of this fault.
A. If the fault is present and active, continue with Step 2.
B. If the fault is no longer present or in an inactive state, the fault may be intermittent and not currently active,
continue to Step 5.
2. Check for other fault codes related to the fuel injection system.
A. If other fault codes are not present, continue with Step
3.
B. If other fault codes are present, resolve them first.
3. Check the condition of the Y-9000 connector X-9007.
Disconnect the engine (EN) harness from the Y-9000 at connector X-9007.
Inspect the connector X-9007 contacts for corrosion, damage and proper connection.
A. If the condition of the X-9007 contacts are good, leave the X-9007 disconnected and continue to Step 4.
B. If the X-9007 is faulty, refer to the appropriate service manual to repair or replace the engine (EN) harness as
necessary.
4. Check the Y-9000 for an internal failure.
Electrical systems - FAULT CODES
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