E37 Outdoor Heat Exchanger Temperature Sensor Anomaly - Mitsubishi SCM40ZS-S Technical Manual

Error code
E37
Remote control:
1. Applicable model
All models
2. Error detection method
Detection of anomalously low
temperature (resistance) on
the outdoor heat exchanger
temperature sensor
3. Condition of error displayed
• When the temperature sensor
detects -55 °C or lower for 20
seconds continuously within
2 minutes to 2 minutes 20
seconds after the compressor
ON, the compressor stops.
After 3-minutes delay, the
compressor starts again
automatically, but if this
anomalous temperature is
detected 3 times within 40
minutes.
• When -55 °C or lower is
detected for within 20 second
after power ON.
4. Presumable cause
• Defective outdoor main PCB
• Broken sensor harness or
temperature sensing section
• Disconnected wire connection
(connector)
Note:
LED Green Red
Keeps flashing Stays OFF
Indoor
– 8-time flash
Outdoor
5. Troubleshooting
Diagnosis
Is the
outdoor heat
exchanger temperature
sensor connector
connected
properly?
YES
For the characteristics of outdoor heat exchanger
temperature sensor, see the following graph.
Are the
characteristics of
outdoor heat exchanger
temperature
sensor
OK?
Temperature-resistance characteristics
(Broken wire)
15
10
5
(Short circuit)
0
262
-
Content
Outdoor heat exchanger
temperature sensor anomaly
NO
NO
YES
5kΩ at 25°C
10 20 30 40 50
Temperature (°C)
-
'16 • SCM-T-199
Countermeasure
Correct connector.
Defective outdoor heat
exchanger temperature
sensor → Replace.
Defective outdoor main
PCB → Replace.
(Defective outdoor heat
exchanger temperature
sensor input circuit)