Outdoor Air Temperature Sensor Anomaly - Mitsubishi Heavy Industries FDT100VNAWVH Service Manual

Error code
Remote control:
E38
Indoor unit
control PCB
Outdoor unit
control PCB
1. Applicable model
All models
2. Error detection method
Detection of anomalously low
temperature (resistance) on
outdoor air temperature
sensor
3. Condition of error displayed
• When the temperature sensor
detects -45°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 -45°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
(Check molding.)
• Disconnected wire connection
(connector)
Note:
LED Green
Keeps flashing
Keeps flashing
5. Troubleshooting
Is
the outdoor air
temperature sensor connector
connected properly?
YES
Is the
characteristics of the
outdoor air temperature
sensor
OK?
Temperature-resistance characteristics
(Broken wire) 35
30
25
20
15
10
5
0
(Short-circuit)
0 10
Temperature (°C)
Red
Content
Outdoor air temperature
Stays OFF
1-time flash
Diagnosis
NO
For the characteristics of outdoor air
temperature sensor, see the following graph.
NO
YES
20 30 40 50
116
- -
'19 • PAC-SM-309
sensor anomaly
Countermeasure
Correct connector.
Defective outdoor
air temperature
sensor ➞ Replace.
Defective outdoor unit main
PCB ➞ Replace.
(Defective outdoor air
temperature sensor
input circuit)