Daikin FTKE25BVM Service Manual page 119

Control Specification
3.16.5 Cooling / Heating Mode Lock
Use the S15 connector to set the unit to only cool or heat.
Setting to only heat (H): Short-circuit pins 1 and 3 of the connector <S15>.
Setting to only cool (C): short-circuit pins 3 and 5 of the connector <S15>.
The following specifications apply to the connector housing and pins.
JST products Housing: VHR-5N
Note that forced operation is also possible in COOL / HEAT mode.
108
Pin: SVH-21T-1, 1
COOL mode (C)
5<C>3<H>1
HEAT mode (H)
(R1397)
Si12-411A
Function and Control