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9-2. SELF-DIAGNOSIS ACTION TABLE
Check Code
Abnormal point and detection method
Cause
Countermeasure
P1
P2
P4
Drain sensor (DS)
1
Suspensive abnormality, if short/open
of thermistor is detected for 30 seconds
continuously. Compressor and indoor fan
will be turned off
2
Short/open is detected for 30 seconds
continuously during suspensive
abnormality.
(The unit returns to normal operation,
if it has normally reset.)
3
Detect the following condition.
• During cooling and drying operation.
• In case that pipe <liquid> temperature
- room temperature <−10
:
(Except
defrosting)
• When pipe <liquid> temperature or
room temperature is short/open
temperature.
• During drain pump operation.
1
Defective thermistor
characteristics
2
Contact failure of connector
(CN31) on the indoor controller
board (Insert failure)
3
Breaking of wire or contact
failure of drain sensor wiring
4
Defective indoor controller board
1
–
3
Check resistance value of thermistor.
0
:
......6.0 k
"
10
:
....3.9 k
"
20
:
....2.6 k
"
30
:
....1.8 k
"
40
:
....1.3 k
"
2
Check contact failure of connector (CN31)
on the indoor controller board. Refer to "9-6.
TEST POINT DIAGRAM". Turn the power on
again and check restart after inserting con-
nector again.
4
Replace indoor controller board if drain
pump operates with the line of drain sensor
connector CN31-
1
and
2
is short-circuited,
and abnormality reappears.
Turn the power off, and on again to operate
after check.
P5
Malfunction of drain pump (DP)
1
Suspensive abnormality, if thermistor
of drain sensor is let heat itself and
temperature rises slightly. Compressor
and indoor fan will be turned off.
2
Drain pump is abnormal if the condition
above is detected during suspensive
abnormality.
3
Constantly detected during drain pump
operation.
1
Malfunction of drain pump
2
Defective drain
Clogged drain pump
Clogged drain pipe
3
Attached drop of water at the
drain sensor
• Drops of drain trickles from
lead wire
• Clogged filter is causing
wave of drain.
4
Defective indoor controller board
1
Check if drain pump operates.
2
Check drain function.
3
Check the setting of lead wire of drain sensor
and check clogs of the filter.
4
Replace indoor controller board if drain
pump operates with the line of drain sensor
connector CN31-
1
and
2
is short-circuited
and abnormality reappears.
Refer to "9-6. TEST POINT DIAGRAM".
Turn the power off, and on again to operate
after check.
Room temperature thermistor (TH1)
1
The unit is in 3-minute resume
prevention mode if short/open of
thermistor is detected. Abnormal if the
unit does not reset normally after 3 min-
utes. (The unit returns to normal opera-
tion, if it has been reset normally.)
2
Constantly detected during cooling,
drying, and heating operation.
Short: −90
:
or more
Open: −40
:
or less
1
Defective thermistor
characteristics
2
Contact failure of connector
(CN20) on the indoor controller
board (Insert failure)
3
Breaking of wire or contact
failure of thermistor wiring
4
Defective indoor controller
board
1
–
3
Check resistance value of thermistor.
0
:
15.0 k
"
10
:
9.6 k
"
20
:
6.3 k
"
30
:
4.3 k
"
40
:
3.0 k
"
If you put force on (draw or bend) the lead wire
with measuring resistance value of thermistor,
breaking of wire or contact failure can be
detected.
2
Check contact failure of connector (CN20)
on the indoor controller board. Refer to "9-6.
TEST POINT DIAGRAM". Turn the power on
again and check restart after inserting con-
nector again.
4
Check room temperature display on remote
controller.
Replace indoor controller board if there is
abnormal difference with actual room
temperature.
Turn the power off, and on again to operate
after check.
Pipe temperature thermistor/Liquid
(TH2)
1
The unit is in 3-minute resume
prevention mode if short/open of
thermistor is detected. Abnormal if the
unit does not reset normally after 3 min-
utes. (The unit returns to normal opera-
tion, if it has been reset normally.)
2
Constantly detected during cooling,
drying, and heating (except defrosting)
operation.
Short: 90
:
or more
Open: −40
:
or less
1
Defective thermistor
characteristics
2
Contact failure of connector
(CN44) on the indoor control-
ler board (Insert failure)
3
Breaking of wire or contact
failure of thermistor wiring
4
Defective refrigerant circuit is
causing thermistor temperature
of 90
:
or more or 3−40
:
or
less.
5
Defective indoor controller
board
1
–
3
Check resistance value of thermistor.
For characteristics, refer to (P1) above.
2
Check contact failure of connector (CN44)
on the indoor controller board. Refer to "9-6.
TEST POINT DIAGRAM". Turn the power on
and check restart after inserting connector
again.
4
Check pipe <liquid> temperature with remote
controller in test run mode. If pipe <liquid>
temperature is extremely low (in cooling
mode) or high (in heating mode), refrigerant
circuit may have defective.
5
Check pipe <liquid> temperature with
remote controller in test run mode. If there is
extremely difference with actual pipe <liquid>
temperature, replace indoor controller board.
Turn the power off, and on again to operate
after check.
Note:
Errors to be detected in outdoor unit, such as codes starting with F, U
or E (excluding E0 to E7), are not covered in this document. Please
refer to the outdoor unit's service manual for the details.
OCH492A
