Check code
Location
of
detection
Description
System status
Check code detection
condition(s)
Check items (locations)
• Check for failure in Pd
pressure sensor.
• Check service valves (gas
side, liquid side) to confirm
full opening.
• Check for failure in outdoor
fan.
• Check for failure in outdoor
fan motor.
• Check outdoor PMV
(PMV1, 2, 3, 4) for
clogging.
• Check indoor/outdoor heat
exchangers for clogging.
• Check for short-circuiting
of outdoor suction/
discharge air flows.
• Check for failure in outdoor
P.C. board (I/F).
• Check for failure in indoor
fan system (possible cause
of air flow reduction).
• Check opening status of
indoor PMV.
• Check indoor-outdoor
communication line for
wiring trouble.
• Check for troble operation
of check valve in discharge
pipe convergent section.
• Check gas balancing SV4
valve circuit.
• Check for refrigerant
overcharging.
Activation of
high-pressure
protection
I/F
All stop
<During cooling operation>
Pd sensor detects pressure
equal to or greater than
3.85 MPa.
<During heating operation>
Pd sensor detects pressure
equal to or greater than
3.6 MPa.
P20
P20
—
Main
remote
controller
Outdoor 7-segment display
Check
code
Sub-code
• Check outdoor service
valves (gas side, liquid
side) to confirm full
opening.
• Check outdoor PMVs
(PMV1, 2, 3, 4) for
clogging.
• Check resistance
characteristics of TD2
sensor.
• Check for failure in 4-way
valve.
• Check SV4 circuit for
leakage.
• Check SV4 circuit (for
wiring or installation trouble
involving SV41 and SV42).
Discharge
temperature
TD2 trouble
I/F
All stop
Discharge temperature
(TD2) exceeds 115 ˚C.
P17
P17
—
• Check for failure in main
body of 4-way valve.
• Check for coil failure in 4-
way valve and loose
connection of its connector.
• Check resistance
characteristics of TS1 and
TE1,TE2 sensors.
• Check output voltage
characteristics of Pd and
Ps pressure sensors.
• Check for wiring trouble
involving TE1 and TL1
sensors.
4-way valve
reversing
trouble
I/F
Detected
outdoor unit No.
All stop
Abnormal refrigerating cycle
data is collected during
heating operation.
P19
P19
- 191 -
Summary of Contents for MMY-MUP0801HT7JP
Page 309: ......