Mitsubishi Electric Mr. SLIM PCA-M71HA2 Service Manual page 16

Check Code Abnormal point and detection method
Remote controller transmission
error(E3)/signal receiving error(E5)
Abnormal if remote controller could not
find blank of transmission path for 6
seconds and could not transmit.
(Check code: E3)
Remote controller receives transmitted
data at the same time and compares the
received and transmitted data. Abnormal
E3
if these data are judged to be different
or
30 continuous times. (Check code: E3)
E5
Abnormal if indoor controller board could
not find blank of transmission path.
(Check code: E5)
Indoor controller board receives trans-
mitted data at the same time and com-
pares the received and transmitted data.
Abnormal if these data are judged to be
different 30 continuous times. (Check
code: E5)
Indoor/outdoor unit communication
error (Signal receiving error)
Abnormal if indoor controller board
cannot receive any signal normally for 6
minutes after turning the power on.
Abnormal if indoor controller board
cannot receive any signal normally for 3
minutes.
Consider the unit abnormal under the
following condition: When 2 or more
indoor units are connected to an outdoor
E6
unit, indoor controller board cannot
receive a signal for 3 minutes from
outdoor controller circuit board, a signal
which allows outdoor controller circuit
board to transmit signals.
Indoor/outdoor unit communication
error (Transmitting error)
Abnormal if "1" receiving is detected 30
E7 times continuously though indoor controller
board has transmitted "0".
Indoor controller board
Abnormal if data cannot be read normally
FB(Fb)
from the nonvolatile memory of the indoor
controller board.
Remote controller control board
Abnormal if data cannot be read
normally from the nonvolatile memory of
E1 the remote controller control board.
or (Check code: E1)
E2
Abnormal if the clock function of remote
controller cannot be operated normally.
(Check code: E2)
OCH753A
Cause
2 remote controllers are set as
"main."
(In the case of 2 remote con-
trollers)
Remote controller is connected
with 2 indoor units or more.
Repetition of refrigerant
address
Defective transmitting receiv-
ing circuit of remote controller
Defective transmitting receiv-
ing circuit of indoor controller
board
Noise has entered into trans-
mission wire of remote control-
ler.
Contact failure, short circuit or,
miswiring (reversed wiring) of
indoor/outdoor unit connecting
wire
Defective transmitting receiv-
ing circuit of indoor controller
board
Defective transmitting receiv-
ing circuit of indoor controller
board
Noise has entered into indoor/
outdoor unit connecting wire.
Defective transmitting receiv-
ing circuit of indoor controller
board
Noise has entered into power
supply.
Noise has entered into outdoor
control wire.
Defective indoor controller
board
Defective remote controller
16
Judgment and action
Set a remote controller to main, and the
other to sub.
Remote controller is connected with only one
indoor unit.
The address changes to a separate setting.
– Diagnose remote controller.
a) When "OK" is displayed, remote control-
lers have no problem.
Turn the power off, and on again to check.
When becoming abnormal again, replace
indoor controller board.
b) When "NG" is displayed, replace remote
controller.
c) When "E3" or "00–66" is displayed, noise
may be causing abnormality.
Note:
Check LED display on the outdoor control
circuit board. (Connect A-control service
tool, PAC-SK52ST.)
Refer to outdoor unit service manual.
Check disconnection or looseness of indoor/
outdoor unit connecting wire of indoor unit or
outdoor unit.
Check all the units in the case of twin triple
indoor unit system.
Turn the power off, and on again to check.
If abnormality occurs again, replace indoor
controller board or outdoor controller
circuit board.
Note:
Other indoor controller board may have defect
in the case of twin triple indoor unit system.
Turn the power off, and on again to check.
If abnormality occurs again, replace indoor
controller board.
Replace indoor controller board.
Replace remote controller.