Robot lawnmower will not start mowing; display shows E1 shortly after power-on.

Safety first: Turn the main power switch off and remove the mower from the lawn. Keep hands away from the blades at all times.

• Check emergency stop button: Ensure the red STOP or E-STOP button on the top cover is fully released. Press it down once and twist or pull (depending on model) to reset. Turn the main power back on and see if E1 clears.
• Inspect lift sensor area: Many Hyundai robot mowers use a lift sensor under the chassis or integrated into the front/rear axle. Check for packed grass, mud, or debris around the sensor brackets and wheels. Clean with a soft brush and dry cloth.
• Check chassis seating: Make sure the upper cover is properly latched and the mower is sitting flat on a level surface. A twisted chassis can falsely trigger the lift sensor.
• Inspect wiring (advanced): With power OFF and battery disconnected, remove the top cover. Locate the lift sensor connector on the main PCB and ensure it is fully seated. Look for pinched or broken wires near the wheel arms.
• Reset the mower: Reconnect battery, turn power on, and perform a system reset from the settings menu if available. If E1 persists after cleaning and checking wiring, the lift sensor or main PCB may need replacement.