Mitsubishi FDC121KXZEN1-W Technical Manual page 253

Error code
Remote control: E37
7-segment display: E37
*1 One time flash (Tho-R), 5 time flash (Tho-SC), 6 time flash (Tho-H)
1. Applicable model
Outdoor unit
2. Error detection method
Detection of anomalously low
temperature (resistance)
of Tho-R or Tho-SC or Tho-H
3. Condition of error displayed
• If -50°C or lower is detected for 5
seconds continuously within 2 minutes to
2 minutes 20 seconds after the compressor
ON, the compressor stops. And after
3 minutes delay, the compressor starts
again automatically, but if this anomalous
temperature is detected 3 times within 40
minutes after the initial detection.
• If -50°C or lower is detected for 5 seconds
continuously within 20 seconds after power ON
4. Presumable cause
• Broken sensor harness or
the internal wire of sensing
section (Check the molded
section as well)
• Disconnection of sensor
harness connection
(connector)
• Outdoor unit control PCB
anomaly
Note:
LED Green Red
Keeps flashing Stays Off
Indoor
Keeps flashing *1
Outdoor
5. Troubleshooting
Diagnosis
Save data for 30 minutes before stopping in Mente PC
Is the
connector of
sensor connected
properly?
YES
Are the
characteristics of
sensor OK?*2
*2
Check several times to prove any poor connection.
Temperature-resistance characteristics of
Outdoor heat exchanger temperature sensor (Tho-R)
Sub-cooling coil sensor (Tho-SC, Tho-H)
Temperature (°C)
251
-
Outdoor unit heat exchanger
Content
temperature sensor (Tho-R) and subcooling coil
temperature sensor (Tho-SC,-H) anomaly
NO
NO
YES
5kΩ at 25°C
-
'20 • KX-T-373
Countermeasure
Check and save the data of
operating conditions.
Check the conditions whether
it occurs immediately after the
power on or during operation
or stopping.
Check the sensed value.
Compare the temperature
on Mente PC with actual
measured value.
Insert the connector
securely.
Replace sensor .
(Tho-SC, Tho-H, Tho-R)
Replace outdoor unit control
PCB.