Mitsubishi Electric FDT125VNVF Technical Manual page 438

Indoor display
Error code
E38
Remote controller:
inverter PCB
1. Applicable model
All models
2. Error detection method
Detection of anomalously
low temperature (resistance)
on outdoor air temperature
thermistor
3. Condition of Error displayed
• When the temperature thermistor
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-minutes
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 control
PCB
• Broken thermistor harness or
temperature sensing section
(Check molding.)
• Disconnected wire connection
(connector)
Note:
RUN light
Keeps flashing
Green LED
Outdoor
control PCB
Keeps flashing
Yellow LED
Outdoor
Keeps flashing
5. Troubleshooting
the outdoor air
temperature thermistor connector
connected properly?
characteristics of the
outdoor air temperature
thermistor
Temperature-resistance characteristics
(Broken wire) 35
30
25
20
15
10
5
0
(Short circuit)
0 10
TIMER light
Content
1 time flash
Outdoor air temperature
Red LED
1 time flash
Diagnosis
Is
YES
For the characteristics of outdoor air
temperature thermistor, see the following graph.
Is the
OK?
YES
20 30 40 50
Temperature (°C)
437 437
- - - -
thermistor anomaly
Countermeasure
Correct connector.
NO
Defective outdoor air
temperature thermistor ➞
NO
Replace.
Defective outdoor control
PCB ➞ Replace.
(Defective outdoor air
temperature thermistor
input circuit)
'12 • PAC-T-174