Kubota E-2 – Tractor ECU / Meter CPU or Auto Idle (AI) Controller: Acceleration sensor (sub) trouble

Indicates a failure, signal loss, or out-of-range reading on the secondary (sub) circuit of the throttle/acceleration sensor. When this sensor fails, the machine will typically exhibit sluggish acceleration, rough idling, engine flutter, or a complete lack of response to throttle inputs.

• M4N-071
• M5N-091
• M5N-111
• M5660SUH
• M7060
• M5091N
• M5101N
• M6060
• M100XDC
• M135GXDTC
• L3240HST
• L4240HST
• L5240HST
• L5740HST
• KX033
• KX057
• KX080
• KX91-3
• KX121-3
• KX161-3
• U30
• U35
• U45
• U48
• U55

1. 1

   Verify the master system warning indicator is blinking and ERROR-2 is actively displayed on the LCD.

2. 2

   Inspect the wiring harness leading to the acceleration sensor for chafed wires, corrosion inside the connector plug, or loose pins.

3. 3

   Verify that the mechanical linkage (the metal tab on the sensor) is still properly seated against the governor lever or accelerator knob support.

4. 4

   On AI-equipped machines, enter Service Mode to check the live input/output voltage signals of the acceleration sensor to confirm a hard failure.

1. 1

   Power Down

   Turn off the machine and disconnect the negative battery cable to prevent electrical shorts and reset the ECU.

2. 2

   Locate the Sensor

   The acceleration sensor is typically attached either directly to the support bracket of the accelerator knob (in the cab/dash area) or mounted on the engine governor assembly, depending on your specific model.

3. 3

   Remove the Old Sensor

   Unplug the electrical connector from the sensor. Remove the mounting screws/bolts holding the sensor housing in place.

4. 4

   Install the New Sensor

   Place the new sensor into position. Ensure the metal tab/actuator arm on the sensor is correctly aligned and placed on the governor lever or throttle knob mechanism. Incorrect physical installation will immediately trigger secondary codes and the throttle will remain unresponsive.

5. 5

   Reassembly

   Tighten the mounting hardware and plug the electrical connector back in.

6. 6

   Calibration/Testing

   Reconnect the battery. Turn the key on and verify the ERROR-2 code has cleared. Test the throttle knob/pedal for smooth engine response. On some AI-equipped models, you may need to run the Auto Idle setup procedure to calibrate the new sensor's sweep.