Panasonic CS-Z25UD3EAW Service Manual page 102

18.4.8 H24 (Indoor Pipe Temperature Sensor 2 Abnormality)
Malfunction Decision Conditions

During startup and operation of cooling and heating, the temperatures detected by the indoor heat exchanger
temperature sensor 2 are used to determine sensor errors.
Malfunction Caused

Faulty connector connection.

Faulty sensor.

Faulty PCB.
Troubleshooting
When abnormality indication starts again.
Check the connector connection:
Plug out connector from the indoor unit PCB.
Measure the resistance of the indoor pipe temperature
sensor.
Is the connector connection normal?
Check the outdoor air temperature sensor:
Plug out connector from the outdoor unit PCB.
Measure the resistance of the outdoor intake air
temperature sensor.
Is the measured resistance of the outdoor intake air
temperature sensor matches the value specified in its
characteristic chart?
Sensor (Thermistor)
Characteristics
70
1 Pipe temp. Sensor
60
2 Intake Air Temp. Sensor
50
1
40
2
30
20
10
0
-10 0 10
(14) (32) (50)
Temperature °C (°F)
YES
YES
20 30 40 50
(68) (86) (104) (122)
For safety reason and to prevent component
breakdown, always switch off the power
Caution
before remove and connect the component.
Connector poor contact.
NO
Correct the connection.
Defect in outdoor intake air temperature sensor.
NO
Replace the outdoor intake air temperature
sensor.
Defect in outdoor unit PCB.
Replace the outdoor unit PCB.
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