Mitsubishi Electric Mr.Slim PLH42AK, Technical & Service Manual

Page: 48 / 73

OC193-46
Check
code
Diagnosis of malfunction Cause Check points
E0
Signal transmitting/receiving
error
Indoor controller does not
respond to remote controller
signal.
During individual unit control
1) Bad contact of transmission
wire
2) Signal transmitting/receiving cir-
cuit is abnormal.
1) Check the transmission wire.
2) Check with another remote controller. If “E0” is
still indicated, replace the indoor controller
board.
If other check code appears. replace the former
remote controller.
P3
Signal transmission error
(Remote controller does not
respond to indoor controller
signal.)
1) Bad contact of transmission
wire
2) Signal transmitting/receiving cir-
cuit is abnormal.
3) Wrong operation of remote con-
troller due to noise wave emit-
ted by other appliances
1) Check the transmission wire.
2) Check with another remote controller.
If “P3” is still indicated, replace the indoor
board.
If other check code appears, replace the origi-
nal remote controller.
3) Short-circuit between
1
and
2
of CN40 and
attach CN40 to the following units.
l
Second unit in twin control
l
Second and third units in triple control
l
Sub units in group control
P4
Abnormality of drain sensor 1) Bad contact of transmission
wire
2) Damaged thermistor
1) Check the connector.
2) Measure the resistance of the thermistor
4
-
5
.
As for the normal resistance, refer to the case
P1.
If normal, replace the indoor controller board.
P5
Malfunction of drain pump 1) Malfunction of drain pump
2) Damaged drain sensor
1) Check the drain pump.
2)
l
Check the drain sensor.
l
Check the drain sensor heater. If normal, its
resistance should be 82
"
.
If normal, replace the indoor controller board.
P6
Coil frost protection has
worked.
1) Short cycle of air cycle
2) Dirty air filter
3) Damaged fan
4) Abnormal refrigerant
1) Clear the obstructions from the air cycle.
2) Clean the air filter
3) Check the fan.
4) Check the refrigerant temperature.
P7
System error 1) Wrong address-setting
2) Signal transmitting/receiving cir-
cuit of remote controller is
abnormal.
3) Wrong SW6-setting
1) Check the address-setting.
2) Check with another remote controller. If check
code other than “P7” appears, replace the origi-
nal remote controller.
3) Check SW6 setting.
P8
Abnormality of outdoor unit 1) Wrong wiring of indoor/outdoor
connecting wire
2) Reversed phase
3) Protection device has worked
4) Damaged outdoor coil thermis-
tor
1) Check the indoor/outdoor connecting wire.
2) Change the connection of electric wiring.
3) Check the detail of the protection device.
4) Measure the resistance of the outdoor coil ther-
mistor. If normal, replace the outdoor controller
board.
P1
P2
Abnormality of room temper-
ature thermistor (RT1)
Abnormality of indoor coil
thermistor (RT2)
1) Bad contact of thermistor
2) Damaged thermistor
1) Check the thermistor.
2) Measure the resistance of the thermistor.
If normal, it should be as follows.
32
-
F····15k
"
86
-
F ··4.3k
"
50
-
F····9.6k
"
104
-
F ··3.0k
"
68
-
F····6.3k
"
If normal, replace the indoor controller board.