Mitsubishi Heavy Industries FDUA160AVSAVH Service Manual page 106

Error code
Indoor control PCB
Remote control: E55
Outdoor control PCB
Outdoor inverter
1. Applicable model
All models
2. Error detection method
When anoumalous low
temperature (resistance) is
detected by the compressor
under dome temperature sensor
3. Condition of error displayed
If the temperature sensor detcts
-50°C or lower for 5 seconds
continuously within 10 minutes
to 10 minutes 20 seconds after
compressor ON, the compressor
stops. When the compressor
is restarted automatically after
3-minute delay, if this anomaly
ocuurs 3 times within 40
minutes.
4. Presumable cause
• Defective under-dome
temperature sensor connection
• Defective under-dome
temperature sensor
• Defective outdoor unit control
PCB
Note:
LED Green
Keeps flashing
Keeps flashing
Yellow LED
PCB
Keep flashing
5. Troubleshooting
connection of
under-dome temperature
sensor connector
characteristics of
under-dome temperature
sensor OK?
Temperature-resistance characteristics
(Broken wire)
15
10
5
(Short-circuit)
Red
Content
Stays OFF
Compressor under-dome
1-time flash
temperature sensor anomaly
Diagnosis
Is the
OK?
YES
For the characteristics of under-dome
temperature sensor, see the following graph.
Are the
YES
5kΩ at 25°C
0 10 20 30 40 50
Temperature (°C)
105
- -
'21 • PAC-SM-398
Countermeasure
Correct connection of
NO
under-dome temperature
sensor connector.
Defective under-dome
NO
temperature sensor
➞Replace.
Replace outdoor unit
control PCB.
(Defective under-dome
temperature sensor input
circuit)