Turn off power completely. Open the front cover of the indoor unit and the side terminal cover of the outdoor unit.

In most documented O General cases:

error often specifically points to a communication error between the remote controller and the indoor unit PCB. Inter-Unit Wiring:

If the code disappears, it was likely a temporary glitch caused by power noise. 2. Inspect Communication Wires

Sudden voltage surges can temporarily scramble the communication signal, triggering the code even if no hardware is broken.