Toshiba MMW-AP0271LQ-E Service Manual page 58

Check code
Main Outdoor 7-segment display
remote
Check
Sub-code
controller
code
P18 P18 —
Detected
outdoor unit No.
P19 P19
P20 P20 —
Location
Description
of
detection
I/F Discharge
temperature
TD3 error
I/F 4-way valve
reversing error
I/F Activation of
high-pressure
protection
Error detection
System status
condition(s)
All stop Discharge temperature
(TD3) exceeds 115 ˚C.
All stop Abnormal refrigerating cycle
data is collected during
heating operation.
All stop Pd sensor detects pressure
equal to or greater than
3.6 MPa.
– 58 –
Indoor unit (including Hot Water Module)
Check items (locations)
• Check outdoor service
valves (gas side, liquid
side) to confirm full opening.
• Check outdoor PMVs
(PMV1, 2, 4) for clogging.
• Check resistance
characteristics of TD3
sensor.
• Check for defect in 4-way
valve.
• Check SV43 circuit for
leakage.
• Check SV4 circuit (for wiring
or installation error involving
SV41, SV42 and SV43).
• Check for defect in main
body of 4-way valve.
• Check for coil defect in 4-
way valve and loose
connection of its connector.
• Check resistance
characteristics of TS1 and
TE1 sensors.
• Check output voltage
characteristics of Pd and
Ps pressure sensors.
• Check for wiring error
involving TE1 and TL
sensors.
• Check for defect in Pd
pressure sensor.
• Check service valves (gas
side, liquid side) to confirm
full opening.
• Check for defect in outdoor
fan.
• Check for defect in outdoor
fan motor.
• Check outdoor PMVs
(PMV1, 2, 4) for clogging.
• Check indoor / outdoor
heat exchangers for
clogging.
• Check for short-circuiting
of outdoor suction /
discharge air flows.
• Check SV2 circuit for
clogging.
• Check for defect in outdoor
P.C. board (I/F).
• Check for defect in indoor
fan system (possible cause
of air flow reduction).
• Check opening status of
indoor PMV.
• Check indoor-outdoor
communication line for
wiring error.
• Check for faulty operation
of check valve in discharge
pipe convergent section.
• Check gas balancing SV4
valve circuit.
• Check SV5 valve circuit.
• Check for refrigerant
overcharging.