Kubota P2229 – Engine ECU: Barometric pressure sensor error (High side)

The Engine ECU has detected that the barometric pressure sensor circuit is shorted to a high power source (+B) or there is an internal ECU circuit short. The fault is logged when the battery voltage is normal, but the barometric pressure sensor output voltage reads abnormally high (4.4 V to 4.85 V or more for 2.8 seconds or longer). The ECU inhibits DPF regeneration, limits engine output (limp mode), and substitutes a default atmospheric pressure value of 65 kPa.

• V3800
• V3307
• V2607
• D1803
• V1505
• M-Series (e.g., M108X, M108S)
• Carrier refrigeration units (e.g., 69UG15)
• Baroness mowers
• Kobelco excavators (e.g., SK200-10)
• MEC Aerial Work Platforms

1. 1

   Connect Kubota Diagmaster, clear DTCs, and cycle the ignition to rule out temporary electromagnetic interference (EMI).

2. 2

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

3. 3

   Monitor the live voltage of the Barometric Pressure Sensor using Diagmaster (normal reading at sea level is approx. 4.0 V; >4.4 V indicates an active short).

4. 4

   Disconnect the sensor and check the wiring harness leading back to the Engine ECU for a short circuit to battery power (+B) on the signal wire.

1. 1

   Safely Shut Down

   Turn the key switch to the OFF position and allow the engine to cool.

2. 2

   Locate the Sensor

   Locate the Barometric/Atmospheric pressure sensor (often located on the intake manifold or integrated into the intake air piping, depending on the exact engine model).

3. 3

   Inspect the Connector

   Disconnect the sensor's pigtail connector. Inspect the pins for corrosion, water intrusion, or bent terminals. Clean with contact cleaner if necessary.

4. 4

   Test the Circuit

   With the sensor disconnected, turn the key to the ON position (engine off). Use a digital multimeter to probe the sensor harness connector. If the signal wire shows full battery voltage (12V), there is a short to power in the wiring harness that must be traced and repaired.

5. 5

   Replace the Sensor

   If the wiring harness tests good (no short to +B) and the ECU connector is undamaged, the sensor itself has failed internally. Replace the Barometric Pressure Sensor.

6. 6

   Clear Codes and Verify

   Reconnect the new sensor. Connect the Kubota Diagmaster tool, clear the P2229 code, and run the engine to verify that the code does not return and that engine output returns to 100%.