Discharge Pipe Temperature Sensor Anomaly - Mitsubishi Heavy Industries FDTC40ZSXVH Service Manual

Error code
Remote control: E39
1. Applicable model
All models
2. Error detection method
Detection of anomalously low
temperature (resistance) on
the discharge pipe temperature
sensor
3. Condition of error displayed
When the temperature sensor
detects -25°C or lower for 5
seconds continuously within
10 minutes to 10 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.
4. Presumable cause
• Defective outdoor unit PCB
• Broken sensor harness or
temperature sensing section
(Check molding.)
• Disconnected wire connection
(connector)
Note:
LED Green Red
Content
Indoor Keeps flashing Stays OFF
Outdoor - 8-time flash
5. Troubleshooting
Diagnosis
Is the
discharge pipe
temperature sensor
connector connected
properly?
YES
For the characteristics of discharge pipe
Are the
temperature sensor, see the following graph.
characteristics
of discharge pipe
temperature
sensor OK?
Temperature-resistance characteristics
(Broken wire)
100
50
0
[T 90 ]
°C
0 20 40
(Short-circuit)
Temperature (°C)
78
- -
Discharge pipe
temperature sensor anomaly
NO
NO
YES
60 80 100 120 140
'18 • PAC-SM-297
Countermeasure
Correct connector.
Defective discharge
pipe temperature
sensor ➞ Replace.
Defective outdoor unit
PCB ➞ Replace.
(Defective temperature
sensor input circuit)