Mitsubishi Electric PURY-P72 Service Handbook page 226

[ IX Troubleshooting ]
1. Error Code
5103
Heat exchanger outlet temperature sensor (TH3) fault (Outdoor unit)
5104
Discharge temperature sensor (TH4) fault (Outdoor unit)
5105
Accumulator inlet temperature sensor (TH5) fault (Outdoor unit)
5106
Heat exchanger inlet temperature sensor (TH6) fault (Outdoor unit)
5107
Outside temperature sensor (TH7) fault (Outdoor unit)
2. Error definition and error detection method
When a short (high temperature intake) or an open (low temperature intake) of the thermistor is detected (the first detection),
the outdoor unit stops, turns to anti-restart mode for 3 minutes, and restarts when the detected temperature of the thermistor.
When a short or an open is detected again (the second detection) after the first restart of the outdoor unit, the outdoor unit
stops, turns to anti-restart mode for 3 minutes, and restarts in 3 minutes when the detected temperature is within the normal
range.
When a short or an open is detected again (the third detection) after the previous restart of the outdoor unit, the outdoor unit
makes an error stop.
When a short or an open of the thermistor is detected just before the restart of the outdoor unit, the outdoor unit makes an
error stop, and the error code "5102", "5103", 5104", "5105", "5106"or "5107" will appear.
During 3-minute antirestart mode, preliminary errors will be displayed on the LED display.
A short or an open described above is not detected for 10 minutes after the compressor start, during defrost mode, or for 3
minutes after defrost mode.
3. Cause, check method and remedy
Cause
(1) Thermistor failure
(2) Pinched lead wire
(3) Torn wire coating
(4) A pin on the male connector is missing or
contact failure
(5) Disconnected wire
(6) Thermistor input circuit failure on the control
board
<Reference>
HWE0803A
Short detection
TH3 110 C [230 F ] and above (0.4 k ) -40 C [ -40 F ] and below (130 k )
TH4 240 C [464 F ] and above (0.57 k )
TH5 70 C [158 F ] and above (0.4 k ) -40 C [ -40 F ] and below (130 k )
TH6 70 C [158 F ] and above (1.14 k ) -40 C [ -40 F ] and below (130 k )
TH7 110 C [230 F ] and above (0.4 k ) -40 C [ -40 F ] and below (130 k )
- 217 -
Check method and remedy
Check thermistor resistance.
Check for pinched lead wire.
Check for wire coating.
Check connector.
Check for wire.
Check the intake temperature of the sensor with the LED
monitor.
When the temperature is far different from the actual temper-
ature, replace the control board.
Open detection
0 C [ 32 F ] and below (698 k )
GB