Interface Unit/Flow Temp. Controller/Outdoor Unit Communication Error; Non Defined Check Code; Serial Communication Error - Mitsubishi Electric PUHZ-SHW230YKA2 Service Manual

Check Code
Abnormal point and detection method
Interface unit/Flow temp. controller
or outdoor unit communication error
(Signal receiving error)
1 Abnormal if Interface unit/Flow temp.
controller cannot receive any signal
normally for 6 minutes after turning the
power on.
2 Abnormal if Interface unit/Flow temp.
E6
controller cannot receive any signal
normally for 3 minutes.
Interface unit/Flow temp. controller
or outdoor unit communication error
(Signal receiving error)
(Outdoor unit)
(1) Abnormal if outdoor controller circuit
board could not receive anything
normally for 3 minutes.
E8
Interface unit/Flow temp. controller
or outdoor unit communication error
(Transmitting error) (Outdoor unit)
(1) Abnormal if "0" receiving is detected
30 times continuously though outdoor
controller circuit board has transmitted
E9
"1".
(2) Abnormal if outdoor controller circuit
board could not find blank of transmis-
sion path for 3 minutes.

Non defined check code

This code is displayed when non defined
check code is received.
EF

Serial communication error

Abnormal if serial communication between
outdoor controller circuit board and outdoor
power circuit board is defective.
Ed
OCH594B
Case
1 Contact failure, short circuit
or, miswiring (reverse wiring)
of Interface unit/Flow temp.
controller or outdoor unit
connecting wire
2 Defective transmitting receiving
circuit of outdoor controller
circuit board
3 Defective transmitting receiving
circuit of Interface unit/Flow
temp. controller
4 Noise has entered into Interface
unit/Flow temp. controller or
outdoor unit connecting wire.
1 Contact failure of Interface unit/
Flow temp. controller or outdoor
unit connecting wire
2 Defective communication circuit
of outdoor controller circuit
board
3 Defective communication circuit
of Interface unit/Flow temp.
controller
4 Noise has entered into Interface
unit/Flow temp. controller or
outdoor unit connecting wire.
1 Interface unit/Flow temp.
controller or outdoor unit
connecting wire has contact
failure.
2 Defective communication circuit
of outdoor controller circuit
board
3 Noise has entered power
supply.
4 Noise has entered Interface
unit/Flow temp. controller or
outdoor unit connecting wire.
1 Noise has entered transmission
wire of remote controller.
2 Noise has entered Interface
unit/Flow temp. controller-
outdoor unit connecting wire.
1 Wire disconnection or contact
failure of connector CN2
between the outdoor controller
circuit board and the outdoor
power circuit board
2 Wire disconnection or contact
failure of connector CN4
between the outdoor controller
circuit board and the outdoor
power circuit board
3 Defective communication circuit
of outdoor power circuit board
4 Defective communication circuit
of outdoor controller circuit
board for outdoor power circuit
board
24
Judgment and action
Note: Check LED display on the outdoor
controller circuit board. (Connect
A-control service tool, PAC-SK52ST.)
1 Check disconnection or looseness of
Interface unit/Flow temp. controller or
outdoor unit connecting wire of Interface unit/
Flow temp. controller or outdoor unit.
2–4 Turn the power off, and on again to check.
If abnormality occurs again, replace
Interface unit/Flow temp. controller or
outdoor controller circuit board.
1 Check disconnection or looseness of
Interface unit/Flow temp. controller or
outdoor unit connecting wire of Interface
unit/Flow temp. controller or outdoor unit.
2–4 Turn the power off, and on again to
check. Replace PCB of Interface
unit/Flow temp. controller or outdoor
controller circuit board if abnormality is
displayed again.
1 Check disconnection or looseness of
Interface unit/Flow temp. controller or
outdoor unit connecting wire.
2–4 Turn the power off, and on again to
check. Replace outdoor controller circuit
board if abnormality is displayed again.
12 Turn the power off, and on again to check.
Replace Interface/FTC or outdoor
controller circuit board if abnormality is
displayed again.
12 Check connection of each connector CN2
and CN4 between the outdoor controller
circuit board and the outdoor power circuit
board.
3 Replace outdoor power circuit board.
4 Replace outdoor controller circuit board.