Robot vacuum shows E4 and stops, usually near stairs or dark carpets.

Safety: Turn off the robot and flip it over onto a soft surface.

• Locate cliff sensors: Identify the downward-facing sensors along the front underside of the robot.
• Clean sensor windows: Use a soft, dry microfiber cloth to gently wipe each sensor window. For stubborn dirt, lightly dampen the cloth with water (no chemicals) and dry immediately.
• Remove heavy dust: Use compressed air to blow out dust from sensor recesses.
• Test on light floor: Place the robot on a light-colored, flat surface away from edges and start a cleaning cycle.
• Check for false triggers: If E4 appears only on very dark or black carpets, the sensors may be overly sensitive; try enabling any "carpet mode" or adjusting settings in the Laresar app if available.
• If E4 persists everywhere: The cliff sensor board or wiring may be defective. Accessing it requires removing the bottom cover and replacing the cliff sensor module.