Outdoor Heat Exchanger Temperature Sensor Anomaly - Mitsubishi FDUA160AVSAWVH Service Manual

Error code
Indoor control PCB
Remote control:
E37
Outdoor control PCB
Outdoor inverter
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:
LED Green
Keeps flashing
Keeps flashing
Yellow LED
PCB
Keeps flashing
5. Troubleshooting
Is the
outdoor heat
exchanger temperature
sensor connector
connected
properly?
YES
Are the
characteristics of
outdoor heat exchanger
temperature sensor
OK?
Temperature-resistance characteristics
(Broken wire)
15
10
5
(Short-circuit)
Red
Content
Stays OFF
exchanger temperature
1-time flash
Diagnosis
NO
For the characteristics of outdoor heat exchanger
temperature sensor, see the following graph.
NO
YES
5kΩ at 25°C
0 10 20 30 40 50
Temperature (°C)
93
- -
'21 • PAC-SM-396
Outdoor heat
sensor anomaly
Countermeasure
Correct connector.
Defective outdoor heat
exchanger temperature
sensor➞Replace.
Defective outdoor unit
control PCB➞Replace.
(Defective outdoor heat
exchanger temperature
sensor input circuit)