Troubleshooting Method - Toshiba MMW-AP0271LQ-E Service Manual

8-2. Troubleshooting method

The remote controllers (main remote controller and central control remote controller) and the interface P.C.
board of an outdoor unit are provided with 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 fault site / faulty part
may be identified in the event of a fault 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 fault in consultation with the list.
• When investigating a fault on the basis of a display provided on the indoor remote controller or TCC-LINK
central control remote controller -
See the "TCC-LINK remote controller or main remote controller display" section of the list.
• When investigating a fault on the basis of a display provided on an outdoor unit - See the "Outdoor 7-
segment display" section of the list.
• When investigating a fault 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)
(Error detected by indoor unit)
Check code
Outdoor 7-segment display
TCC-LINK
central control
or main remote
controller
display
A01 A01 Detected indoor nuit No.
A02 A02 Detected indoor nuit No.
A04 A04 Detected indoor nuit No.
E03 —
E04 —
E08 E08 Duplicated indoor address
E10 —
E18 —
F01 —
F03 —
F19 —
F25 —
F26 —
F29 —
L03 —
L07 —
L08 L08
L09 —
L20 —
L30 Detected indoor unit No.
L30
P31 —
Typical fault site
Sub-code
Flow switch operation error
Water temperature decrease
error
Activation of water heat
exchanger frost protection
Indoor-remote controller periodic
—
communication error
Indoor-outdoor periodic
—
communication error
Duplicated indoor address
Indoor inter-MCU communication
—
error
Error in periodic communication
—
between indoor header and
follower unit
Indoor heat exchanger
—
temperature sensor (TCJ) error
Indoor heat exchanger
—
temperature sensor (TC1) error
Indoor heat exchanger
—
temperature sensor (TF) error
Indoor heat exchanger
—
temperature sensor (TA) error
Indoor heat exchanger
—
temperature sensor (TC2) error
— P.C. board or other indoor error
Duplicated indoor group header
—
unit
Connection of group control cable
—
to stand-alone indoor unit
— Indoor group address not set
— Indoor capacity not set
— Duplicated central control address There is duplication in central control address setting.
Indoor external error input
(interlock)
— Other indoor unit error
IPDU: Intelligent Power Drive Unit (Inverter P.C. board)
Indoor unit (including Hot Water Module)
When water flow rate is reduced.
Water temperature continued the low status regardless of that
the heater pump is operating.
Frost protection for water heat exchanger is activated
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 faulty.
Periodic communication between indoor header and follower units
cannot be maintained.
Heat exchanger temperature sensor (TCJ) has been open /
shortcircuited.
Heat exchanger temperature sensor (TC1) has been open /
shortcircuited.
Heat exchanger temperature sensor (TF) has been open /
shortcircuited.
Heat exchanger temperature sensor (TA) has been open /
shortcircuited.
Heat exchanger temperature sensor (TC2) has been open /
shortcircuited.
Indoor EEPROM is abnormal (some other error may be 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.
Unit shutdown has been caused by external error input (CN80).
Follower unit cannot be operated due to header unit alarm (E03 /
L03 / L07 / L08).
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Description of error