Mitsubishi Heavy Industries FDT100VNAWVH Service Manual page 159

Error code
Indoor display
Remote control:
E37
Outdoor unit
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 -50°C or lower for 20
seconds continuously within 2
minutes to 2 minutes 20 seconds
after the compressor ON, the
compressor stops. After 3-minute
delay, the compressor starts again
automatically, but if this anomalous
temperature is detected 3 times
within 40 minutes.
• When -50°C or lower is detected for 5
seconds continuously within 20 second
after compressor ON.
4. Presumable cause
• Defective outdoor unit main
PCB
• Broken sensor harness or
temperature sensing section
• Disconnected wire connection
(connector)
Note:
RUN light
Keeps flashing
Green LED
control PCB
Keeps flashing
5. Troubleshooting
outdoor heat
exchanger temperature
sensor connector
connected
properly?
Are the
characteristics of
outdoor heat exchanger
temperature
sensor OK?
(Broken wire)
(Short-circuit)
TIMER light
Content
2-time flash
Outdoor heat exchanger
Red LED
temperature sensor anomaly
1-time flash
Diagnosis
Is the
YES
For the characteristics of outdoor heat exchanger
temperature sensor, see the following graph.
YES
Temperature-resistance characteristics
15
10
5k at 25°C
5
0 10 20 30 40
Temperature (°C)
158
- -
'19 • PAC-SM-309
Countermeasure
Correct connector.
NO
Defective outdoor heat
NO
exchanger temperature
sensor ➞ Replace.
Defective outdoor unit
main PCB ➞ Replace.
(Defective outdoor heat
exchanger temperature
sensor input circuit)
50