Mitsubishi Electric Mr. SLIM MSZ-FA25VA Technical Manual página 764

Resolución de averías
Meaning of error code and detection method
Error Code
Abnormality of pipe temperature ther-
mistor / Condenser-Evaporator (TH5)
1 The unit is in three-minute resume pro-
tection mode if short/open of thermistor
is detected. Abnormal if the unit does
not get back to normal within three min-
utes. (The unit returns to normal opera-
tion, if it has normally reset.)
2 Constantly detected during cooling, dry-
ing, and heating operation (except
defrosting)
Short: 90:
Open: -40:
P9
764
1 Defective thermistor
2 Contact failure of connector
3 Breaking of wire or contact
4 Temperature of thermistor is
5 Defective indoor controller
or more
or less
Cause
characteristics
(CN29) on the indoor controller
board. (Insert failure)
failure of thermistor wiring.
90: or more or -40: or less
caused by defective refrigerant
circuit.
board.
Countermeasure
1 –3 Check resistance value of thermistor.
For characteristics, refer to (P1) above.
2 Check contact failure of connector (CN29)
on the indoor controller board.
Refer to 10-6.
Turn the power on and check restart after
inserting connector again.
4 Operate in test run mode and check pipe
<condenser / evaporator> temperature with
outdoor controller circuit board. If pipe
<condenser / evaporator> temperature is
exclusively low (in cooling mode) or high (in
heating mode), refrigerant circuit may have
defective.
5 Operate in test run mode and check pipe
<condenser / evaporator> temperature with
outdoor control circuit board. If there is
exclusive difference with actual pipe
<condenser / evaporator> temperature
replace indoor controller board.
There is no abnormality if none of above
comes within the unit.
Turn the power off and on again to operate.
( In case of checking pipe temperature
with outdoor controller circuit board,
be sure to connect A-control service
tool (PAC-SK52ST).
)