SiUS331708EA
Troubleshooting
CHECK 11
CHECK 12
Service Diagnosis
Be sure to turn off the power switch before connecting or disconnecting
Caution
connectors, or parts may be damaged.
Is it cooling?
NO
Is the
temperature
difference between the suction
YES
pipe and the outdoor heat
exchanger greater than
20˚C (68˚F)?
NO
CHECK 11
Is the resistance
NO
measured from suction pipe
thermistor disconnected from
the outdoor unit PCB
normal?
YES
Is the low pressure
NO
sensor normal?
YES
Refer to page 266.
Refer to page 269.
Is the low
YES
pressure less or equal to 0.25 MPa
(36.3 psi)?
NO
CHECK 12
Is the voltage between
X18A pins (2) and (3) of outdoor
main PCB (A1P) less or equal to 1.0 VDC?
(Low pressure sensor output
voltage)
NO
Troubleshooting by Error Code
YES
Short of refrigerant, closed stop
valve, or blocked cooling
system. Check the refrigerant
system.
YES
Replace the outdoor main
PCB (A1P).
Replace the low pressure
sensor (S1NPL).
Short of refrigerant or blocked
cooling system. Check the
refrigerant system.
Replace the suction pipe
thermistor.
Replace the low pressure
sensor (S1NPL).
Replace the outdoor main
PCB (A1P).
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