Safety first: Turn the robot OFF and flip it over on a soft surface.

Step-by-step:

Inspect both drive wheels: Rotate each large side wheel by hand. They should spin smoothly with some resistance from the motor.
Remove hair and debris: Use scissors or a seam ripper to cut away hair wrapped around the wheel axles and inside the wheel wells. Pull debris out with tweezers.
Check wheel travel: Press each wheel up and down. It should move freely in its suspension. If it sticks, clean the sliding surfaces and remove any lodged dirt.
Test on flat floor: Place the robot on a hard, flat surface and start a cleaning cycle. Avoid thick rugs while testing.
Advanced checks: If one wheel is weak or not turning, remove the bottom cover to access the left/right wheel motor module. Check the motor connector to the main PCB. If the motor smells burnt, is seized, or the encoder disc is broken, replace the affected drive wheel motor assembly.

When to stop: If the wheel module is damaged or the robot still reports E3 after cleaning, a replacement wheel motor assembly is required.

Robot vacuum reports E3 and stops; often described as wheel stuck, side wheel error, or wheel suspended.

Possible Causes