Robot mower shows E4 and stops when approaching boundary wire

Safety: Turn OFF the mower and unplug the charging station from mains power before working on the boundary system.

• Check charging station LEDs: Refer to the Makita manual; a flashing or off loop indicator often means a boundary break.
• Inspect visible wire: Walk the perimeter and check for cut or exposed boundary wire, especially where aeration, edging, or pets may have damaged it.
• Test wire continuity: Use a basic multimeter set to continuity or resistance. Disconnect both ends of the boundary wire at the station and measure across them. Infinite resistance indicates a break.
• Repair breaks: Use genuine Makita-compatible waterproof boundary connectors to join broken sections. Bury or peg the repaired section securely.
• Check station terminals: Clean any corrosion from the boundary wire terminals on the charging station and re-tighten connections.
• Power up and test: Plug in the station, verify loop indicator is normal, then power ON the mower and clear the E4 error.

If the loop indicator remains abnormal and wiring is intact, the charging station’s boundary transmitter module may be faulty and require replacement.