Case IH 3703 – Engine ECU: Injection control: check of minimum rail pressure.

The minimum fuel rail pressure value necessary to allow fuel injection has not been reached. The engine controller has detected that the high-pressure fuel system is failing to build or maintain the required pressure to start or run the engine properly.

• skid steer
• SV300
• SR175
• 580N
• 580 Super N
• Farmall 95U
• Farmall 115U
• Puma
• Maxxum
• Steiger

1. 1

   Verify the fuel tank is not empty

2. 2

   Check for air entering the system by installing a clear line at the inlet of the high-pressure pump to observe for air bubbles while cranking/running

3. 3

   Inspect the primary fuel filter (water separator) and secondary fuel filter for severe clogging or water contamination

4. 4

   Test the low-pressure supply between the fuel filter and the high-pressure pump (minimum specification is typically around 5 bar / 72 psi)

5. 5

   Check if the Pressure Control Valve (PCV) is stuck in the open or closed position, or if there is an electrical problem/short in its wiring harness

6. 6

   Verify the electrical resistance and wiring of the fuel rail pressure sensor

1. 1

   Resolve Supply Issues

   If the low-pressure supply test fails, inspect all low-pressure fuel lines for kinks or leaks. Replace the primary and secondary fuel filters.

2. 2

   Bleed the System

   After replacing filters, thoroughly bleed the fuel system to ensure no air is trapped in the lines.

3. 3

   Test/Replace Lift Pump

   If low-pressure supply is still below 5 bar (72 psi) after filter replacement, replace the low-pressure fuel lift pump.

4. 4

   Inspect the PCV / Pressure Limiting Valve

   If the low-pressure side is functioning correctly, inspect the Pressure Control Valve on the high-pressure pump and the pressure relief valve on the fuel rail. If the return line from the PCV is clogged or the valve is bypassing too much fuel, replace the valve.

5. 5

   Leak-off Test

   If the PCV is functioning, perform a leak-off test on the fuel injectors to see if an injector is stuck open and dumping rail pressure back into the return system.

6. 6

   Replace High-Pressure Pump

   If all other components pass inspection, the high-pressure injection pump itself has failed internally and must be replaced.

7. 7

   Clear Codes

   Use the OEM service tool to clear the fault codes and test run the machine to verify the repair.