Robot vacuum starts, then stops within a few seconds and shows C02.

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

• Clean wheel areas: Flip the robot over. Use a small brush and compressed air to clean around the drive wheels, especially near the inner side where the encoder disk and sensor are located (often partially visible through slots).
• Check for wobble: Rotate each wheel slowly by hand. If you feel grinding or see the wheel wobble, the encoder disk or motor shaft may be damaged and the motor assembly should be replaced.
• Inspect harness (if accessible): On some Samsung models, you can remove the bottom cover to access the motor harness. Ensure the connectors are fully seated in the main PCB.
• Test again: Reassemble, power on, and start a cleaning cycle. If C02 reappears, the affected drive motor assembly or main PCB encoder circuit is likely defective and should be replaced by a technician.