Robot lawnmower shows E15 and stops near obstacles; may not detect collisions properly.

Safety first: Turn off the mower before cleaning or handling sensors.

• Clean sensor windows: Wipe the front ultrasonic sensor lenses or grills with a soft, damp cloth to remove dirt and grass stains.
• Check for cracks: Inspect the sensor housings for cracks that could allow water ingress. Replace damaged housings.
• Inspect wiring: Remove the top cover and locate the ultrasonic sensor cable. Ensure it is firmly connected to the main PCB and not pinched.
• Dry out moisture: If the mower was pressure-washed or submerged, allow the sensor area to dry thoroughly before retesting.
• Replace sensor: If E15 persists and the mower fails to detect obstacles, replace the Hyundai ultrasonic sensor module.