Troubleshooting Method - Toshiba MMY-MUP0721HT9P-UL Service Manual

8-2. Troubleshooting method

The remote controllers (main remote controller and central remote controller) and the interface P.C. board of an
outdoor unit have an LCD display (remote controller) or 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 problem in consultation with the list.
• When investigating a problem on the basis of a display provided on the indoor remote controller or central
remote controller See the "Remote control or main remote controller display" section of the list.
• When investigating a problem on the basis of a display provided on an outdoor unit - See the "Outdoor 7-
segment display" section of the list.
• When investigating a problem on the basis of a wireless remote controller-controlled indoor unit - See the
"Light sensor indicator light block" section of the list.
List of Check Codes (Indoor Unit)
(Check code detected by indoor unit)
Check code
Central control Outdoor 7-segment display
or main remote
controller
Sub-code
display
E03 — —
E04 — —
Duplicated indoor
E08 E08
address
E10 — —
E11 — —
E18 — —
F01 — —
F02 — —
F03 — —
F10 — —
F11 — —
F29 — —
L03 — —
L07 — —
L08 L08 —
L09 — —
L20 — —
Detected indoor unit
L30 L30
No.
P01 — —
P10 Detected indoor unit
P10
No.
P12 — —
P31 — —
Display of receiving unit
Indicator light block
Typical problem site
Ready
Operation Timer
Flash
Indoor-remote controller
periodic communication
trouble
Indoor-outdoor periodic
communication trouble
Duplicated indoor address
Indoor inter-MCU
communication trouble
Communication check code
between Application control
kit and indoor unit
Trouble in periodic
communication between indoor
header and follower unit
Indoor heat exchanger
temperature sensor (TCJ)
ALT
trouble
Indoor heat exchanger
temperature sensor (TC2)
ALT
trouble
Indoor heat exchanger
temperature sensor (TC1)
ALT
trouble
Room air temperature sensor
ALT
(TA/TSA) trouble
Discharge air temperature
ALT
sensor (TF/TFA) trouble
P.C. board or other indoor
SIM
trouble
SIM Duplicated indoor group
header unit
Connection of group control
SIM
cable to stand-alone indoor unit
SIM Indoor group address not set
SIM Indoor capacity not set
Duplicated central control
SIM
address
Indoor external trouble input
SIM
(interlock)
ALT Indoor AC fan trouble
ALT Indoor overflow trouble
ALT Indoor DC fan trouble
ALT Other indoor unit trouble
- 169 -
: Lighting, : Flashing, : Goes off
ALT.: Flashing is alternately when there are two flashing LED
SIM: Simultaneous flashing when there are two flashing LED
Description of Check code
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.
MCU communication between main controller and
motor microcontroller is failure.
Communication check code between Application
control kit and indoor unit P.C. board.
Periodic communication between indoor header
and follower units cannot be maintained.
Heat exchanger temperature sensor (TCJ) has
been open/short-circuited.
Heat exchanger temperature sensor (TC2) has
been open/short-circuited.
Heat exchanger temperature sensor (TC1) has
been open/short-circuited.
Room air temperature sensor (TA) has been
open/short-circuited.
Discharge air temperature sensor (TF) has been
open/short-circuited.
Open/Short-circuit of indoor air suction temperature
sensor (TRA) was detected.
There is more than one header unit in group.
There is at least one stand-alone 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 duplication in central control address
setting.
Unit shutdown has been caused by external trouble
input (CN80).
Indoor AC fan trouble is detected (activation of fan
motor thermal relay).
Float switch has been activated.
Indoor DC fan trouble (e.g. overcurrent or lock-up)
is detected.
Follower unit cannot be operated due to header unit
alarm (E03/L03/L07/L08).