Check code
5106
(U4)
Ambient temperature thermistor (TH7) open/short
Abnormal points and detection methods
Causes and checkpoints
If TH7 detects to be open/short
Open: −40 [−40°F] or less
Short: 90 [162°F] or more TH7: Thermistor <Ambient>
Disconnection or contact failure of connectors
Characteristic defect of thermistor
Defective outdoor multi controller circuit board
●Diagnosis of defects
Make sure to turn the power OFF before connecting/disconnecting
any connectors, or replacing boards.
Diagnosis
Remedy
The black square (■) indicates a switch position.
SW1 Setting
ON
OFF
Display on LED1, 2
Unit
−99.9–999.9
_
C
4
1 2
5 6 7 8
3
No
Yes
Yes
Yes
No
No
Is there any abnormality such
as disconnection, looseness or
breakage?
Is the detected resistance normal?
Is the detected temperature normal?
Connect the wiring/connector properly.
Replace it in the case of breakage.
Replace the thermistor.
Replace the outdoor multi controller circuit
board (Malfunction of thermistor circuit).
No abnormality
(A connector contact failure is suspected.)
Check the wiring and connector connection of TH7.
Disconnect the connector to check the
resistance of TH7 using a multimeter.
Check the temperature of TH7.
The detected temperature of thermistor (TH7) can be
displayed by an operation of SW1 on the outdoor multi
controller circuit board.
The detected temperature of TH7 can be displayed by an
operation of SW1 on the outdoor multi controller circuit board.
83
OCH673D
