Mitsubishi SCM40ZS-S Technical Manual page 273

Error code
Remote control: E57
1. Applicable model
All models
2. Error detection method
• Judge insufficient refrigerant
amount by detecting the
temperature differnce between
indoor heat exchanger (Thi-R)
and indoor return air (Thi-A).
3. Condition of error displayed
When the insufficient refrigerant
amount is detected 3 times
within 60 minutes.
4. Presumable cause
• Defective indoor heat
exchanger temperature
thermistor
• Defective indoor return air
temperature thermistor
• Defective indoor control PCB
• Insufficient refregerant
amount
Note:
LED Green Red
Indoor Keeps flashing Stays OFF
– 2-time flash
Outdoor
5. Troubleshooting
Diagnosis
Is the
service valve fully
opened?
YES
Are the
connections of indoor
heat exchanger and/or return air
temperature thermistor
connectors OK?
YES
Are the
characteristics of indoor heat
exchanger and/or return air
temperature thermistor
OK?
YES
Is the low
pressure during operation
normal?
Indoor heat exchanger, return air temperature thermistor
Temperature-resistance characteristics
(Broken wire)
15
10
5
(Short circuit)
0
272
-
Content
Insufficient refrigerant amount
or detection of service valve closure
NO
NO
NO
NO
YES
5kΩ at 25°C
10 20 30 40 50
Temperature (°C)
-
'16 • SCM-T-199
Countermeasure
Open fully.
Correct indoor heat
exchanger, return air
temperature thermistor
connector connections.
Defective indoor heat
exchanger, return air
temperature thermistor →
Replace.
Charge refrigerant.
Defective indoor control
PCB → Replace. (Defective
indoor heat exchanger,
return air temperature
thermistor input circuits)