Mitsubishi Electric Mr.Slim PMH-P25BA Service Manual page 15

Error Code Meaning of error code and detection method
Indoor/outdoor unit communication
error (Signal receiving error)
1 Abnormal if indoor controller board
cannot receive any signal normally for
six minutes after putting the power on.
2 Abnormal if indoor controller board
cannot receive any signal normally for
three minutes.
E6
3 Consider the unit abnormal under the
following condition: When two or more
indoor units are connected to one
outdoor unit, indoor controller board
cannot receive a signal for three 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".
Abnormality of remote controller con-
trol board
1 Abnormal if data cannot be normally
read from the nonvolatile memory of the
E1 remote controller control board.
(Error code: E1)
or
E2
2 Abnormal if the clock function of remote
controller cannot be normally operated.
(Error code: E2)
Cause
1 Contact failure, short circuit or,
mis-wiring (converse wiring) of
indoor/outdoor unit connecting
wire
2 Defective transmitting receiving
circuit of indoor controller board
3 Defective transmitting receiving
circuit of indoor controller board
4 Noise has entered into indoor/
outdoor unit connecting wire.
1 Defective transmitting receiving
circuit of indoor controller board
2 Noise has entered into power
supply.
3 Noise has entered into outdoor
control wire.
1 Defective remote controller.
15
Countermeasure
∗ Check LED display on the outdoor control cir-
cuit board. (Connect A-control service tool,
PAC-SK52ST.)
Refer to EA-EC item if LED displays EA-EC.
1 Check disconnection or looseness of indoor/
outdoor unit connecting wire of indoor unit or
outdoor unit.
Check all the units in case of twin triple
indoor unit system.
2-4 Turn the power off, and on again to
check. If abnormality generates again,
replace indoor controller board or outdoor
controller circuit board.
∗ Other indoor controller board may have
defective in case of twin triple indoor unit
system.
1-3 Turn the power off, and on again to
check. If abnormality generates again,
replace indoor controller board.
1 Replace remote controller.