Indoor Unit - Mitsubishi Electric SUZ-M-VA Series Service Manual

2. Table of indoor unit failure mode recall function
NOTE: Blinking patterns of this mode differs from the ones of Troubleshooting check table (10-4.).
Left lamp of Right lamp of
OPERATION OPERATION
INDICATOR lamp INDICATOR lamp
Not lit Not lit
1-time blink
Not lit
every 0.5-second
2-time blink
Not lit
2.5-second OFF
3-time blink
Not lit
2.5-second OFF
11-time blink
Not lit
2.5-second OFF
12-time blink
Not lit
2.5-second OFF
13-time blink
Not lit
2.5-second OFF
OBH843
Abnormal point
(Failure mode)
Normal
The room temperature thermistor
Room temperature
short or open circuit is detected every 8
thermistor
seconds during operation.
The indoor coil thermistor short or
Indoor coil thermistor
open circuit is detected every 8 seconds
(Main 1, 2 and sub)
during operation.
The serial signal from the outdoor unit is
Serial signal error
not received for a maximum of 6 minutes.
The rotational frequency feedback
Indoor fan motor (Upper)
signal is not emitted during 12-second the
indoor fan operation.
It cannot properly read data in the
nonvolatile memory of the indoor electronic
Indoor control system
control P.C. board.
The indoor coil thermistor short or
Indoor coil thermistor
open circuit is detected every 8 seconds
(Main 3)
during operation.
Condition
–
27
Remedy
–
Refer to the characteristics of the room
temperature thermistor (11-7.).
Refer to the characteristic of the main
indoor coil thermistors 1 and 2 and the
sub indoor coil thermistor (11-7.).
Refer to 11-6. "How to check miswiring
and serial signal error".
Refer to 11-6 "Check of indoor
fan motor.
Replace the indoor electronic control
P.C. board.
Refer to the characteristic of the main
indoor coil thermistor 3 (11-7.).