Outdoor Heat Exchanger Temperature Sensor Anomaly - Mitsubishi Heavy Industries SRK20ZJX-S Service Manual

Error code
Remote controller:
E37
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
Indoor Keeps flashing Stays OFF
Outdoor – 8 times flash
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
(Shot circuit)
0
102
-
Content
Outdoor heat exchanger
temperature sensor anomaly
NO
NO
YES
5k at 25°C
10 20 30 40 50
Temperature (°C)
-
'10 • SCM-SM-094
Countermeasure
Correct connector.
Defective outdoor heat
exchanger temperature
sensor Replace.
Defective outdoor main
PCB Replace.
(Defective outdoor heat
exchanger temperature
sensor input circuit)