Robot vacuum reports 'Error 2' / voice prompt 'Error 2: Main wheel error' and stops, often stuck on thresholds or carpets.

Safety first: Turn off the robot and remove it from the dock before working on the wheels.

• 1. Free the robot:
  • Lift the robot off any threshold, cable, or rug edge.
  • Place it on a flat, hard surface.
• 2. Inspect both drive wheels:
  • Flip the robot over.
  • Check around each large side wheel for hair, threads, or debris wrapped around the axle.
  • Use scissors or tweezers to carefully cut and pull out any entangled material.
• 3. Test wheel movement:
  • Manually press each wheel up and down; it should move smoothly and spring back.
  • Rotate each wheel by hand; it should turn freely without grinding or binding.
• 4. Clean wheel wells and sensors:
  • Use a small brush or compressed air to clean dust from the wheel wells.
  • On some Xiaomi models, wheel encoders are optical; avoid touching the encoder discs but blow dust away gently.
• 5. Run a test:
  • Power the robot back on and start a spot clean.
  • If one wheel does not move or the error returns immediately, the wheel motor or encoder assembly may be defective.
• 6. Advanced repair:
  • Remove the bottom cover (several screws) to access the wheel module.
  • Disconnect the wheel module cable from the mainboard and inspect for damage or corrosion.
  • Replace the entire wheel module if the motor or encoder is faulty.