E20
Segway Ultrasonic or ToF Obstacle Sensor Fault

Mower displays E20 and stops when entering a narrow passage or complex area.

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Safety Warning

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

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Possible Causes

Dirty or blocked ultrasonic sensor windows, Damaged sensor housing from impact, Loose sensor connector, Failed ultrasonic/ToF sensor module

How to Fix / Troubleshooting

Safety first: Turn OFF the mower and disconnect the battery before cleaning or replacing sensors.

  • Locate sensors: Identify the front‑mounted ultrasonic or time‑of‑flight (ToF) sensors on the mower’s bumper or body.
  • Clean sensor faces: Wipe the sensor windows with a soft, damp cloth to remove dust, grass juice, or mud. Dry thoroughly.
  • Inspect for cracks: Check the sensor housings for impact damage or water ingress points.
  • Check wiring: Open the front cover and verify that the sensor harness is firmly connected to the main board.
  • Test in open area: After cleaning, operate the mower in a wide, obstacle‑free area to see if E20 reoccurs.
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Repair Difficulty

Medium 3/5

Required Part

Front Ultrasonic/ToF Sensor Module
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