Kubota E:9100 – Engine Control Module (ECM / ECU): Rpm sensor system

Indicates an issue with the engine's Crankshaft Position Sensor (also referred to as the RPM speed sensor or revolution sensor). The Engine Control Module (ECM) logs this code when it detects an erratic, missing, or out-of-range signal from the sensor, which is critical for monitoring engine speed and timing. When this code is active, the machine will typically go into a derate mode, resulting in limited engine performance, limited acceleration, or rough running.

• SVL65-2
• SVL75-2
• SVL90-2
• SVL95-2
• SVL97-2
• SSV65
• SSV75
• R630

1. 1

   Inspect the crank position sensor for magnetic interference by removing it and checking for small metallic particles or shavings accumulated on the tip.

2. 2

   Check the wiring harness leading to the sensor for chafed wires, loose connector pins, or rodent damage (pay special attention to the resistor wired into the harness near the sensor).

3. 3

   Verify that the sensor is receiving its reference voltage and has a solid ground.

4. 4

   Test the sensor signal using an oscilloscope or multimeter; brushing a metal object across the tip with the key on should produce a measurable signal change, and the sensor voltage should toggle between 0V and 5V as the flywheel teeth pass by.

1. 1

   Locate the Sensor

   Find the RPM speed sensor located on the engine block, near the crankshaft/flywheel housing.

2. 2

   Remove the Sensor

   Disconnect the electrical connector. Remove the retaining bolt and carefully pull the sensor out of the housing.

3. 3

   Clean and Inspect

   Wipe the sensor port clean. If you are reusing the sensor, thoroughly clean all metallic debris from the magnetic tip.

4. 4

   Install the New Sensor

   Insert the new sensor into the housing.

5. 5

   Alignment (If applicable)

   According to the SVL75-2 Workshop Manual, if the sensor requires alignment, rotate the flywheel to align the sensor with the missing teeth on the pulsar gear. The standard reference is the 14th tooth from the missing teeth, where the voltage should momentarily change from 0 to 5V.

6. 6

   Secure and Reconnect

   Tighten the retaining bolt and plug the electrical connector back in.

7. 7

   Clear Codes

   Start the machine to verify the rough running condition is resolved. Depending on the machine's software version, the code may clear itself after a few successful run cycles, or it may require a dealer to clear it using Kubota's diagnostic software (Diagmaster).