Roborock robot vacuum announces “Error 4” / “Cliff sensor error” and refuses to move or backs away from normal floor.
Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
Possible Causes
How to Fix / Troubleshooting
Safety first: Power off the robot and turn it upside down on a soft surface.
Step-by-step:
- Clean sensor windows: Locate the downward-facing cliff sensors along the front underside. Wipe each window with a soft, dry microfiber cloth. Do not use wet cleaners directly on the sensors.
- Blow out dust: Use compressed air to blow out any dust from the sensor recesses.
- Test on light-colored floor: Place the robot on a light, non-reflective surface (e.g., light tile or wood) away from direct sunlight and start a cleaning cycle.
- Adjust environment: If the error only occurs on very dark or black carpets, consider using no-go zones in the app or boundary settings to keep the robot off those areas.
If cleaning does not help: The cliff sensor PCB or wiring harness may be defective. Internal access is required to test and replace the sensor board.
Repair Difficulty
Required Part
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