Kubota P0264 – Engine Control Unit (ECU): Cylinder 2 Injector Circuit Low

The engine's computer has detected a voltage reading that is below the expected threshold (typically dropping below 4.0 volts on the low side) or a complete loss of the 12V feed in the electrical circuit controlling the #2 cylinder's fuel injector. This condition prevents the injector from receiving the necessary electrical pulse to open and atomize fuel properly, leading to a dead cylinder, rough idling, misfires, and loss of power.

• V2403
• V3307
• V3800
• D1803
• D1105
• D902
• L-Series
• L3901
• L4701
• L3940
• L4600
• M-Series
• B-Series
• KX-Series
• KX71-3
• KX121-3ST
• KX161-3ST
• U-Series
• RTV1100
• RTV1140
• ZD-Series
• R-Series

1. 1

   Use an OBD-II or Kubota-specific diagnostic scan tool to confirm P0264 is active. Check for accompanying misfire codes (e.g., P0302).

2. 2

   Inspect the wiring harness leading to the #2 fuel injector. Look for chafed wires, rodent damage, melted insulation, or loose/corroded connector pins.

3. 3

   Turn the ignition ON (engine off) and use a multimeter to verify that the injector connector is receiving the proper 12V supply voltage.

4. 4

   Disconnect the #2 injector and measure the resistance across its terminals. An infinite reading indicates an internal open circuit (blown coil), while a reading of 0 indicates an internal short.

5. 5

   While the engine is running, place a mechanic's stethoscope against the #2 injector. If it is not clicking, it is not actuating.

6. 6

   Check the continuity of the ground wire from the injector harness back to the ECU pin to rule out a broken wire.

1. 1

   Disconnect Power

   Disconnect the negative battery cable to prevent electrical shorts while working on the ECU or fuel system.

2. 2

   Access the Injector

   Remove any engine covers, intake piping, or brackets obstructing access to the fuel rail and cylinder #2 (the second cylinder in the firing order).

3. 3

   Address Wiring (If Applicable)

   If the diagnostic checks revealed a broken wire or corroded connector, splice in a new injector connector pigtail using heat-shrink butt connectors, or clean the terminals with electrical contact cleaner.

4. 4

   Remove the Faulty Injector

   If the injector itself failed the resistance test, disconnect its electrical connector. Loosen and remove the high-pressure fuel line fitting at the injector and the fuel rail. Remove the injector hold-down clamp/bolt.

5. 5

   Extract and Clean

   Carefully pull the injector out of the cylinder head. Clean the injector bore, ensuring no debris falls into the cylinder. Remove the old copper crush washer if it stuck in the bore.

6. 6

   Install the New Injector

   Place a new copper crush washer and O-ring on the new OEM injector. Seat it into the bore and torque the hold-down clamp to Kubota's factory specifications.

7. 7

   Reassemble

   Reconnect the high-pressure fuel line (torque to spec) and plug in the electrical connector.

8. 8

   Prime and Clear

   Reconnect the battery. Bleed the fuel system if required by your specific engine model. Use your scan tool to clear the P0264 code, start the engine, and check for fuel leaks and a smooth idle.