Mitsubishi Electric · PAR-21MAA MA Remote Controller
The indoor unit has detected an error in receiving signals from the remote controller. This could be due to issues with the remote controller's wiring, the indoor unit's receiving circuit, or external electrical noise disrupting the communication line.
Click steps to track your progress.
Verify the connecting wire between the indoor unit and remote controller is connected correctly at both ends.
Inspect the transmission wire of the remote controller for signs of electrical noise interference.
Cycle power to the unit (turn off, then on again) to re-check for the error.