Daikin RZQ Series FCQ20EVA Service Manual page 120

Troubleshooting by Remote Controller
A
Is it in cooling operation?
YES
(In cooling)
Is the
pressure sensor (∗1)
properly connected to the
outdoor unit PCB?
YES
CHECK 5 Measure voltage between
the connector pins (1) and (3) of the
connector.
CHECK 5
Is the relation between low
pressure and voltage
normal?
YES
Note:
1, 2 Connector and outdoor unit PCB
1 Connector for pressure sensor
CHECK 3 Refer to P.155.
CHECK 4 Refer to P.156.
CHECK 5 Refer to P.157.
111
NO (In heating)
exchanger thermistor (∗2) properly
connected to the outdoor
NO
Remove the thermistor from the
outdoor unit PCB and measure
resistance between the pins (5) and (6).
NO
Is low pressure
abnormally low?
CHECK 3
YES
2 Connector for intermediate heat exchanger
X17A
Is the
intermediate heat
NO
unit PCB?
YES
Is it normal?
NO
CHECK 4
YES
NO
thermistor
X12A
SiME281501E
Connect the connector properly.
Connect the connector properly.
Replace the group thermistor.
Replace the pressure sensor.
Replace the outdoor unit PCB
(A1P).
∗ Replace the PCB
equipped with resin case.
Correct the refrigerant system
defect.
PCB
A1P
Service Diagnosis