Mitsubishi Electric PU(H)Y-P250YGM-A Service Handbook page 134

Temperature sensor failure (indoor unit)
Error definition and error
Error Code
5101 Air inlet If a short or an open is
detected during thermo-
5102 Liquid pipe
stat ON, the outdoor unit
turns to anti-restart mode
5103 Gas pipe
for 3 minutes. When the
error is not restored after
3 minutes (if restored, the
outdoor unit runs normal-
5104 Air outlet
ly), the outdoor unit
makes an error stop.
*Sensor error at gas-side
cannot be detected un-
der the following condi-
tions.
detection method
(1) Thermistor failure
(2) Connector contact failure
(3) Disconnected wire or par-
(4) Unattached thermistor or
(5) Indoor board (detection
Short:
detectable at
90°C or higher
Open :
detectable at
-40°C or lower
During heating oper-
ation
During cooling
operation for 3
minutes after the
compressor turns
on.
- 125 -
Cause
tial disconnected ther-
mistor wire
contact failure
circuit) failure
[ IX Troubleshooting ]
Check method and remedy
Check the thermistor resistor.
0°C : 15 kohm
10°C : 9.7 kohm
20°C : 6.4 kohm
30°C : 4.3 kohm
40°C : 3.1 kohm
Check the connector contact.
When no fault is found, the indoor
board is a failure.