Safety first: Low‑risk fault; standard precautions only.

Reduce interference: Test the robot away from direct sunlight and strong halogen or incandescent lighting.
Clean IR window: Wipe the front/top area where the IR receiver is located with a soft cloth.
Test with app: If the app controls work but the remote does not, the issue may be with the remote or IR receiver only.
Replace remote first: If possible, test with a known‑good remote. If C18 persists, the IR receiver or main PCB likely needs replacement.

Robot vacuum shows C18 and may not respond correctly to remote or app commands.

Possible Causes