Robot mower displays E3 and will not start mowing cycle

Safety: Switch OFF main power and place the mower on a flat, level surface.

• Check placement: Ensure the mower is fully resting on all wheels and not hung up on a curb, root, or obstacle.
• Inspect lift sensor area: On Makita robot mowers, the lift sensor is typically integrated into the chassis or front section. Check for debris or grass buildup preventing the chassis from sitting fully down.
• Gently press chassis: Press down on the mower body to see if the error clears when restarted. If pressing changes the behavior, the lift sensor or its mounting may be loose.
• Check for loose connections: If you are comfortable opening the top cover (following the service instructions), inspect the lift sensor connector and wiring harness for disconnection or corrosion.
• Reset: Turn power ON and attempt to start a manual mow cycle.

If E3 remains, the lift sensor assembly should be tested and replaced by a Makita service center to ensure safe operation.