Mitsubishi Electric City Multi PQHY-P72 Service Handbook page 240

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 heat source
unit turns to anti-restart
5103 Gas pipe
mode for 3 minutes.
When the error is not re-
stored after 3 minutes (if
restored, the heat source
5104 Outdoor air
unit runs normally), the
temperature
heat source unit makes
an error stop.
Short :
detectable at
90°C [194°F] or high-
er
Open :
detectable at
er
Sensor error at gas-side
cannot be detected un-
der the following condi-
tions.
ation
ation for 3 minutes
after the compressor
turns on.
(OA processing unit)
Error definition and error
Error Code
5104 Outdoor air
temperature
detection method
(1) Thermistor failure
(2) Connector contact failure
(3) Disconnected wire or par-
tial disconnected ther-
mistor wire
(4) Unattached thermistor or
contact failure
(5) Indoor board (detection
circuit) failure
-40°C [-40°F] or low-
During heating oper-
During cooling oper-
detection method
- (1) The connector (CN29) is
not connected tightly.
(2) The outdoor air tempera-
ture sensor is broken.
- 231 -
Cause Check method and remedy
Check the thermistor resistor.
0°C [32°F] : 15 kohm
10°C [50°F] : 9.7 kohm
20°C [68°F] : 6.4 kohm
30°C [86°F] : 4.3 kohm
40°C [104°F] : 3.1kohm
Check the connector contact.
When no fault is found, the indoor
board is a failure.
Cause Check method and remedy
Check the contact of the connector.
Replace the sensor.
[ IX Troubleshooting ]