AL-KO robot mower displays E3 and does not move from its position.

Safety first: Turn off the main switch and, if possible, remove the battery connector before working near the wheels.

• Inspect wheels: Spin each drive wheel by hand. If one is stiff or locked, check for stones, twine, or compacted grass between the wheel and chassis. Remove all debris.
• Check wheel treads: Look for foreign objects embedded in the tire that could jam against the body.
• Clean wheel housings: Use a brush and compressed air (if available) to clear grass from the wheel motor area.
• Check motor wiring: Remove the side covers to access the wheel motors. Inspect the motor connectors for loose pins or corrosion. Reseat the connectors firmly.
• Swap test (if possible): On some AL-KO models, you can swap left and right wheel motor connectors at the main PCB to see if the error follows the motor. If it does, the motor/gearbox is faulty.
• Test run: Reassemble, power on, and start a manual drive test. If E3 persists on the same side, replace the affected wheel motor assembly.