Troubleshooting Method - Toshiba MMW-UP0271LQ-E 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 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 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
Sub-code
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 — —
—
E11 —
—
E18 —
F01 — —
F02 — —
F03 — —
—
F10 —
—
F11 —
F19 — —
F25 — —
F26 — —
—
F29 —
—
F30 —
L03 — —
L07 — —
L08
L08 —
—
L09 —
L20 — —
L30 L30 Detected indoor unit No.
—
P01 —
P10
P10 Detected indoor unit No.
—
P12 —
P31 — —
Typical trouble on site
Flow switch operation trouble
Water temperature decrease trouble
Activation of water heat exchanger frost protection
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
Check cod in periodic communication between
indoor header and follower unit
Indoor heat exchanger temperature sensor (TCJ)
check code
Indoor heat exchanger temperature sensor (TC2)
check code
Indoor heat exchanger temperature sensor (TC1)
check code
Ambient temperature sensor (TA) check code
Discharge temperature sensor (TF) check code
Indoor heat exchanger temperature sensor
(TCJ2 (TF)) trouble
Water inlet temperature sensor (TWI (TA)) trouble
Water outlet temperature sensor (TWO (TC2))
trouble
P.C. board or other indoor check code
Occupancy sensor trouble
Duplicated indoor group header unit
Connection of group control cable to a single indoor
unit
Indoor group address not set
Indoor capacity not set
Duplicated central control address
Indoor external check code input (interlock)
Indoor AC fan check code
Indoor overflow check code
Indoor DC fan check code
Other indoor unit check code
– 46 –
Indoor unit (including Hot Water Module)
Description of check code
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.
Communication trouble between main MCU and the motor
microcomputer MCU.
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-circuit.
Heat exchanger temperature sensor (TC2) has been open
/ short-circuit.
Heat exchanger temperature sensor (TC1) has been open
/ short-circuit.
Ambient temperature sensor (TA) has been open /
short-circuit.
Discharge temperature sensor (TF) has been open /
short-circuit.
Heat exchanger temperature sensor (TCJ2 (TF)) has been
open / short-circuited.
Water inlet temperature sensor (TWI (TA)) has been
open / short-circuited.
Water outlet temperature sensor (TWO (TC2)) has been
open / short-circuited.
Indoor EEPROM is abnormal (some other trouble may be
detected).
Occupancy sensor trouble has been detected.
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 duplication in central control address setting.
Unit shutdown has been caused by external check code
input (CN080).
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).