Robot mower will not start mowing and displays 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.

• Check emergency stop button: If your AL-KO model has a red stop button, press it firmly and release. Make sure it is not jammed or contaminated with dirt. Clean around it with a dry brush.
• Inspect mower position: Place the mower on a flat, level surface. If it was on a slope or stuck on an obstacle, the lift/tilt sensor may have triggered. Power cycle the mower and see if the error clears.
• Check chassis and wheels: Ensure the mower is not resting on its housing or front bumper. All wheels should be firmly on the ground.
• Inspect lift sensor wiring: With power off and battery disconnected (if accessible), remove the top cover according to the user manual. Locate the lift/tilt sensor near the front or center of the chassis and check for loose or damaged connectors. Reseat the plug firmly.
• Reset and test: Reassemble the cover, turn the main switch on, and start a manual mowing cycle from the control panel. If E1 persists, the lift sensor module or safety board is likely defective and should be replaced.