Kubota P2112 – Engine Control Unit (ECU): Unable to Reach Higher TPS (Throttle Position Sensor)

This fault code indicates a throttle actuator control system malfunction where the throttle plate is stuck closed or is at a lower angle than commanded by the engine controller.

• Kubota WG1605
• Kubota WG1903
• Kubota WG2503
• Kubota WG3800
• Kubota WG972
• Kubota D1105
• Kubota D1305
• Genie lifts
• JLG boom lifts
• Toro mowers
• Crown equipment

1. 1

   Inspect the throttle body for physical binding, carbon buildup, or debris that could cause the throttle plate to stick closed

2. 2

   Verify that TPS1 reads low voltage when the throttle is closed

3. 3

   Check the wiring harness and connectors leading to the throttle body for open circuits, shorts, or physical damage

4. 4

   Ensure the equipment's battery voltage is consistently above 9.0V, as low voltage can trigger false TPS faults

1. 1

   Clean the Throttle Body

   Disconnect the battery. Remove the air intake hose to access the throttle body. Use a throttle body cleaner and a soft brush to carefully clean the throttle plate and bore to remove any binding carbon deposits.

2. 2

   Test Operation

   Reassemble the intake, reconnect the battery, and clear the fault codes using a Kubota diagnostic tool (like KGST/DST-i). Run the engine to see if the code returns.

3. 3

   Replace the Throttle Body

   If cleaning does not resolve the binding, or if the internal TPS sensors are confirmed faulty via multimeter/diagnostic tool testing, the entire throttle body assembly must be replaced.

4. 4

   Recalibrate

   After replacing the throttle body, use the Kubota diagnostic software to clear the codes and allow the ECU to relearn the new throttle minimum and maximum stop positions.