Robot vacuum stops and displays E4; may announce 'Wheel error' or 'Drive wheel blocked'.

Safety first: Power OFF the robot and remove it from the dock. Work on a stable table or floor.

• Inspect wheels: Check both left and right drive wheels for trapped hair, threads, or carpet fibers around the axles and inside the wheel wells.
• Clean around axles: Use tweezers or a small brush to remove debris from the wheel shafts and the gaps between the wheel and chassis.
• Test suspension: Press each wheel up and down. It should move freely and spring back. If a wheel is stuck in the up or down position, inspect for lodged debris or broken suspension components.
• Rotate wheels manually: Spin each wheel by hand. They should rotate smoothly with slight resistance. Grinding or binding indicates internal gearbox damage.
• Reset and test: After cleaning, turn the robot ON and start a short cleaning run on a flat surface. Observe if it moves without error.
• If E4 persists: The affected drive wheel motor assembly or its encoder may be faulty. Replacement of the complete wheel module is usually required and is best done by a service technician.