General Assist Technical Reference
2/3 Wire Remote Controller Error 12.1 (C012 or C12)
Remote controller DIP switch and wiring check
If Error 12.1, C012 or C12 is displayed, check that the indoor unit PCB remote-controller DIP switch is set for the type of controller being installed. The available settings are 2WIRE and 3WIRE.
1. Check the PCB DIP switch
Set the remote-controller DIP switch on the printed circuit board (PCB) to match the connected controller type.
| Remote controller type | Required DIP switch position |
|---|---|
| 2-wire | 2WIRE |
| 3-wire | 3WIRE - factory setting shown in the source material |
2. Confirm remote controller wiring
Earth connection: Earth (ground) the remote controller if the controller has an earth (ground) wire.
3. What happens when the DIP setting is incorrect?
| Connected controller | Incorrect PCB setting | Result |
|---|---|---|
| 2-wire remote controller | 3WIRE | Power will not be supplied. |
| 3-wire remote controller | 2WIRE | A communication error will be detected. |
4. Quick check for Error 12.1 / C012 / C12
| 1 | Identify whether the installed remote controller is a 2-wire or 3-wire type. |
| 2 | Check the indoor unit PCB DIP switch and confirm it is set to the corresponding 2WIRE or 3WIRE position. |
| 3 | Check the remote-controller cable is connected to the correct Y terminals for the controller type. |
| 4 | If the controller has an earth wire, confirm the earth connection is provided. |
Key point: The controller type, PCB DIP switch position and terminal wiring must all correspond. A mismatch can result in either loss of controller power or a communication fault.