Kubota P0092 – Engine Control Module (ECM): FP High Voltage

The Engine Control Module (ECM) has detected an abnormally high voltage signal from the Fuel Pressure (FP) sensor (exceeds 4.90 volts for 5 seconds), indicating a short to power or internal sensor malfunction. This causes the ECM to enforce a Low Rev Limit.

• WG1605
• WG1903
• WG2503
• WG3800
• WG972

1. 1

   Inspect the wiring harness leading to the Fuel Pressure Manifold (FPM) sensor for chafed wires, melted insulation, or pinched areas that could cause a short to power.

2. 2

   Disconnect the FP sensor and inspect the pins for corrosion, moisture, or damage.

3. 3

   Using a multimeter or diagnostic scan tool, monitor the FP sensor voltage with the key ON. If the voltage is pegged above 4.90V, disconnect the sensor. If the voltage drops, the sensor is internally shorted. If the voltage remains high on the signal wire while disconnected, the wiring harness is shorted to a power source.

1. 1

   Safety First

   Turn off the engine, remove the key, and disconnect the negative battery cable. Ensure you are in a well-ventilated area, as you will be working near the gasoline fuel system.

2. 2

   Locate the Sensor

   Locate the Gasoline Fuel Pressure Manifold (FPM) assembly. On Kubota WG systems, this manifold is typically mounted to the chassis between the external electric fuel pump and the gasoline injector rail.

3. 3

   Relieve Fuel Pressure

   Safely relieve the fuel system pressure to prevent fuel spray.

4. 4

   Remove the Sensor

   Disconnect the electrical connector from the fuel pressure sensor. Unthread the faulty sensor from the manifold assembly.

5. 5

   Install the New Sensor

   Thread the new OEM fuel pressure sensor into the manifold and tighten to the manufacturer's torque specification.

6. 6

   Reassembly

   Reconnect the electrical harness to the sensor. Reconnect the negative battery cable.

7. 7

   Prime and Leak Check

   Turn the ignition key to the ON position (without starting the engine) to prime the electric fuel pump. Inspect the manifold and sensor for any fuel leaks.

8. 8

   Clear Codes

   Use a diagnostic scan tool to clear the P0092 fault code from the ECM. Start the engine and verify that the code does not return and the engine revs normally without the Low Rev Limit restriction.