Capture the message in context
Record the characters exactly, including spaces, dots, alternating messages, and flashing lights. A short video can show an alternating display if you can record it safely without restarting the equipment. Note whether the message appears on the head, remote, wall controller, or app. Those locations matter.
Add the mode, selected temperature, measured room temperature, time since startup, and whether the system is still heating or cooling. Share the indoor, outdoor, and controller model numbers from records or safely visible labels. If you cannot reach a label safely, leave that for the technician.
Use the correct official table
Ask the service provider to identify the official user or service document that covers the installed combination and the display you recorded. A user manual may not contain every service code. A web search for the same two characters on another model is not enough.
We would want a written answer to two questions: what the display means on this equipment, and whether the observed behavior fits that meaning. If it is a normal status, ask for the expected sequence and when a prolonged state needs attention. If it is a fault, ask for the diagnosis and evidence before approving a replacement part. A code identifies an investigation path; it is not proof that a particular component must be replaced.
Your next step: Send the exact display evidence and model details to the installer or qualified ductless provider. Request the matching official explanation and a next step tied to the actual behavior.