Kubota P2228 – Engine ECU: Barometric pressure sensor error (Low side)

The Engine ECU has detected a short to ground in the barometric pressure sensor or its internal circuit. The code is triggered when the battery voltage is normal, but the barometric pressure sensor voltage drops to 1.6 V or less for 2.8 seconds or more. The engine enters a protection/limp mode defaulting the barometric pressure reading to 65 kPa (9.43 psi), causing the engine warning light to turn on, loss of power, and increased white smoke.

• SVL65-2
• SVL75-2
• SVL90-2
• SVL95-2S
• SVL97-2
• SSV65
• SSV75
• KX040-4
• KX057-4
• KX080-4
• U48-5
• U55-4
• M108X
• L3301
• B-series
• BX-series

1. 1

   Connect a computer to the Engine ECU using Kubota's Diagmaster software, clear the DTC, and check if the code returns to rule out temporary electromagnetic interference.

2. 2

   Verify that the machine's battery voltage is normal, as low system voltage can skew sensor readings.

3. 3

   Inspect the wiring harness between the barometric pressure sensor and the Engine ECU for a short to ground or a connector connection fault.

4. 4

   Use Diagmaster to monitor the live voltage of the barometric pressure sensor (a continuous reading of 1.6 V or less indicates a failed sensor or shorted wiring).

1. 1

   Turn the key switch to the OFF position to ensure no power is flowing to the Engine ECU.

2. 2

   Locate the barometric/intake air pressure sensor on the engine intake manifold.

3. 3

   Disconnect the sensor's electrical connector and inspect the pins for corrosion, moisture, or damage.

4. 4

   Using a multimeter, test the wiring harness for continuity to ground. If a short to ground is found in the harness, repair or replace the damaged wiring section.

5. 5

   If the wiring and connector are in good condition and no short is present in the harness, the internal circuit of the sensor has failed. Remove the mounting hardware securing the sensor.

6. 6

   Install the new OEM barometric pressure sensor and secure it.

7. 7

   Reconnect the electrical connector.

8. 8

   Turn the ignition switch to the RUN position, connect the Diagmaster software, and clear the P2228 fault code.

9. 9

   Start the engine and verify that the engine warning light remains off and that full engine output is restored.