Mitsubishi FDT100VNXWVH Service Manual page 156

Error code Indoor display
Remote control:
E37
Outdoor unit
Outdoor unit
inverter PCB
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 5
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 seconds
after compressor ON.
4. Presumable cause
• Defective outdoor unit control
PCB
• Broken sensor harness or
temperature sensing section
• Disconnected wire connection
(connector)
Note:
RUN light
Keeps flashing
Green LED
Keeps flashing
control PCB
Yellow LED
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
1-time flash
temperature sensor anomaly
Diagnosis
Is the
YES
For the characteristics of outdoor heat exchanger
temperature sensor, see the following graph.
YES
Temperature-resistance characteristics
15
10
5kΩ at 25°C
5
0 10 20 30 40
Temperature (°C)
155
- -
'20 • PAC-SM-351
Countermeasure
Correct connector.
NO
Defective outdoor heat
NO
exchanger temperature
sensor ➞ Replace.
Defective outdoor unit
control PCB ➞ Replace.
(Defective outdoor heat
exchanger temperature
sensor input circuit)
50