Troubleshooting Method - Toshiba MMU-UP0071MH-UL Service Manual

9-2. Troubleshooting method

The remote controllers (main remote controller and central control device) and the interface P.C. board of an outdoor unit
are provided with an a 7-segment display (outdoor interface P.C. board) to display operational status. Using this self-
diagnosis feature, the trouble site / trouble part may be identified in the event of a trouble by following the method
described below.
The list below summarizes check codes detected by various devices. Analyze the check code according to where it is
displayed and work out the nature of the trouble in consultation with the list.
• When investigating a trouble on the basis of a display provided on the indoor remote controller or central control device
- See the "central control device or main remote controller display" section of the list.
• When investigating a trouble on the basis of a display provided on an outdoor unit - See the "Outdoor 7- segment
display" section of the list.
• When investigating a trouble on the basis of a wireless remote controller-controlled indoor unit - See the "Indicator light
block" section of the list.
List of check codes (indoor unit)
(Check code detected by indoor unit)
Check code
Outdoor 7-segment display
Remote
controller
display Sub-code
—
E03 —
E04
—
—
E08 E08 Duplicated indoor address
E10 — —
E11 — —
E17 — —
—
E18 —
F01 — —
— —
F02
F03
— —
F10 —
—
F11 — —
F29
—
—
F30
—
—
L03
—
—
L07
— —
L08 L08 —
L09
— —
L20 —
—
L22 — —
L30 L30 Detected indoor unit No.
P01 — —
P10 P10 Detected indoor unit No.
P12 — —
P31
—
—
Display of receiving unit
Indicator light block
Typical trouble on site
Operation
Timer Ready
Flash
Indoor-remote controller periodic
communication check code
Indoor-outdoor periodic
communication check code
Duplicated indoor address
Communication trouble
between indoor unit MCU
Communication check code
between Application control kit
and indoor unit
Communication trouble
between indoor unit(s) and
Flow Selector (FS) unit(s)
Check cod in periodic
communication between indoor
header and follower unit
Indoor heat exchanger
temperature sensor (TCJ) check
ALT
code
Indoor heat exchanger
temperature sensor (TC2)
ALT
check code
Indoor heat exchanger
ALT temperature sensor (TC1)
check code
Ambient temperature
ALT
check code
Discharge temperature sensor
ALT
(TF) check code
P.C. board or other indoor
SIM
check code
ALT Occupancy sensor trouble
Duplicated indoor group header
SIM
unit
Connection of group control cable
SIM
to a single indoor unit
SIM Indoor group address not set
SIM Indoor capacity not set
SIM Duplicated central control address There is duplication in central control address setting.
DX-kit (heat source capacity
SIM command) non-compliant
equipment in the group.
Indoor external check code
SIM
input (interlock)
ALT Indoor AC fan check code
ALT Indoor overflow check code
ALT Indoor DC fan check code
ALT Other indoor unit check code
IPDU: Compressor / Fan inverter P.C. board
: Lighting, : Flashing,
ALT.: Flashing is alternately when there are two flashing LED
SIM: Simultaneous flashing when there are two flashing LED
Communication from remote controller or network adaptor
has been lost (so has central control communication).
Signals are not being received from outdoor unit.
Indoor unit detects address identical to its own.
Communication trouble between main MCU and the motor
microcomputer MCU
Communication check code between Application control
kit and indoor unit P.C. board
There is no communication from FS unit(s).
Periodic communication between indoor header and
follower units cannot be maintained.
Heat exchanger temperature sensor (TCJ) has been open
/ short-circuit.
Heat exchanger temperature sensor (TC2) has been open
/ short-circuit.
Heat exchanger temperature sensor (TC1) has been open
/ short-circuit.
sensor (TA) Ambient temperature sensor (TA) has been open /
short-circuit.
Discharge temperature sensor (TF) has been open /
short-circuit.
Indoor EEPROM is abnormal (some other trouble may be
detected).
There is no signal from Occupancy sensor.
There is more than one header unit in group.
There is at least one a single indoor unit to which group
control cable is connected.
Address setting has not been performed for one or more
indoor units (also detected at outdoor unit end).
Capacity setting has not been performed for indoor unit.
There is a DX-kit (heat source capacity command) non-
compliant equipment in the group. (DDC control, TA control
and TF control are mixed.)
Unit shutdown has been caused by external check code
input (CN80).
Indoor AC fan check code is detected (activation of fan
motor thermal relay).
Float switch has been activated.
• Indoor DC fan check code (e.g. overcurrent or lock-up)
is detected.
Follower unit cannot be operated due to header unit alarm
(E03 /L03 / L07 / L08).
– 86 –
: Goes off
Description of check code