Kubota P2123 – Engine Control Module (ECM): FPP1 Voltage Low

The Engine Control Module (ECM) detects that the signal voltage from the primary electronic foot pedal/throttle control sensor (FPP1) has dropped below the acceptable minimum threshold, causing the machine to illuminate the Malfunction Indicator Lamp (MIL) and enter a fail-safe Limp Mode.

• SVL65-2
• SVL75-2
• SVL90-2
• SVL95-2S
• SVL97-2
• SSV65
• SSV75
• KX040-4
• KX057-4
• KX080-4
• U55-4
• L3901
• L4060
• L4760
• M6
• M7
• MX4800
• MX5400

1. 1

   Inspect the electronic foot pedal sensor connector for water intrusion, corrosion, bent pins, or debris.

2. 2

   Inspect the wiring harness between the pedal sensor and the ECM for chafing, pinches, open circuits, or a short to ground.

3. 3

   Verify that the sensor is receiving the proper 5V reference supply from the ECM and that the sensor ground is intact.

4. 4

   Connect a scan tool, turn the key ON (engine off), and monitor the live data for 'Foot Pedal Position 1'. Slowly depress the pedal to see if the voltage sweeps smoothly. If the voltage remains stuck low (near 0V) despite a good 5V supply and ground, the sensor has failed internally.

1. 1

   Disconnect Battery

   Turn off the ignition and disconnect the negative battery cable.

2. 2

   Access the Pedal Assembly

   Locate the accelerator pedal assembly in the operator's cab.

3. 3

   Disconnect the Sensor

   Unplug the electrical connector from the Foot Pedal Position sensor.

4. 4

   Remove the Sensor/Pedal

   Depending on the machine model, you can either unbolt the sensor directly from the side of the pedal bracket, or you may need to unbolt the entire accelerator pedal assembly from the floorboard.

5. 5

   Install the New Part

   Mount the new sensor or complete pedal assembly and torque the mounting hardware to spec.

6. 6

   Reconnect

   Plug the electrical connector back into the sensor and reconnect the battery.

7. 7

   Clear Codes

   Turn the key ON, use a diagnostic scan tool to clear the P2123 fault code, and verify that the throttle responds normally without triggering the code again.