Robot vacuum reports E3 and stops, often when transitioning between surfaces or near obstacles.

Safety: Turn off the robot and remove it from the dock.

• Check bumper movement: Gently press the front bumper in and release it. It should move freely and spring back without sticking.
• Clean bumper gap: Use compressed air or a soft brush to clean the gap between the bumper and the body. Remove any lodged debris (plastic, toys, cables).
• Wipe sensors: On many Laresar models, infrared collision sensors are located behind the bumper window. Wipe the front bumper window with a soft, dry cloth to remove dust and fingerprints.
• Inspect for damage: Look for cracks or deformation in the bumper that could cause it to bind.
• Reset the robot: Power cycle the robot (turn off, wait 30 seconds, turn on) and start a test clean in an open area.
• If E3 continues: The internal bumper switch or sensor board may be faulty or disconnected. This requires removing the top cover and front assembly to access the bumper PCB and wiring.