Robot vacuum shows E20 and will not start due to an internal sensor bus error.

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.

Possible Causes

Loose sensor harness, Shorted sensor module, Main PCB sensor interface failure

Safety first: Turn OFF the robot, remove it from the dock, and disconnect the battery before opening.

Inspect internal harnesses: Remove the bottom cover and check all sensor harness connectors (cliff sensors, IMU, wheel encoders) to the main PCB. Reseat each connector.
Look for pinched wires: Ensure no harness is pinched between the shell and chassis.

If E20 persists after reseating connectors, a sensor module or the main PCB may be faulty. Professional diagnosis is recommended.

Professional Required 5/5

Sensor Harness / Main PCB

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