Kubota E:9304 – Engine ECU (Engine Control Unit): Engine fuel system (supply pump) / Supply pump error high pressure

The engine is not receiving the correct fuel pressure from the high-pressure supply pump (injection pump) in the common rail fuel system. The underlying condition is typically fuel starvation caused by a restriction in the low-pressure fuel delivery side (such as a clogged filter), a failing electric lift pump, or a mechanical failure of the high-pressure supply pump itself.

• SVL65-2
• SVL75
• SVL75-2
• SVL95-2
• SVL95-2s
• SVL97-2
• SSV65
• SSV65P
• SSV65PC
• SSV75
• SSV75P
• SSV75PC
• R540

1. 1

   Check the fuel level to ensure the machine has adequate diesel fuel.

2. 2

   Inspect the fuel filters and fuel water separator for clogs, gelled fuel, or water.

3. 3

   Check the electric lift pump (filler pump) to verify it is operating and pushing fuel to the high-pressure supply pump.

4. 4

   Inspect fuel lines for pinched areas, leaks, or places where air might be entering the fuel system.

1. 1

   Park and Prep

   Park the machine on a level surface, lower the lift arms, turn off the engine, and allow it to cool.

2. 2

   Drain the Separator

   Locate the fuel water separator and drain any accumulated water or sediment from the bowl.

3. 3

   Replace Fuel Filters

   Remove and replace the main spin-on fuel filter and the water separator filter element. Ensure the mating surfaces are clean and the new filter gaskets are lightly lubricated with clean diesel fuel before installation.

4. 4

   Prime the Fuel System

   Turn the ignition key to the "ON" position (without starting the engine) to allow the electric lift pump to run. This will prime the system and bleed out trapped air.

5. 5

   Test Run

   Start the engine and monitor the dash. If the E:9304 code clears and full engine power is restored, the issue was a clogged filter.

6. 6

   Further Diagnosis (If Code Persists)

   If "E:9304" still appears, immediately contact your local dealer. The dealer will test the low-pressure lift pump output and the high-pressure supply pump. If the supply pump has failed, it must be replaced.