Toshiba MMU-AP0071MH Service Manual page 70

Check code Check code name
[E31] IPDU communication error
Auxiliary code :
01: IPDU1 error 02: IPDU2 error
03: IPDU1, 2 error 04: Fan IPDU error
05: IPDU1, fan IPDU error 06: IPDU2, fan IPDU error
07: All IPDU error or communication line error between IPDU-I/F P.C. boards, or outdoor I/F P.C. board error
If the fan IPDU is abnormal, be sure to check the voltage output on the fan power supply P.C. board.
Is jumper lead setup of the outdoor I/F P.C. board correct?
(Jumper 7, 8, 9 ON)
YES
Are communication connectors
between I/F, fan power supply board,
and IPDU connected?
NO
Is there no disconnection of communication line
between I/F, fan power supply board, and IPDU?
NO
Is there voltage deflection between
4 and 5 pins of CN600 on I/F P.C. board?
(Measurement with tester: DC 0 to 5V, 5 pin GND)
YES
Is there voltage deflection between
3 and 5 pins of CN600 on I/F P.C. board?
(Measurement with tester: DC 0 to 5V, 5 pin GND)
YES
On the fan power supply P.C. board,
1) CN503: Between 1 and 5 pins 12V
2) CN503: Between 2 and 5 pins 7V
3) Between +5V and GND at the side of CN505: 5V
YES
Replace P.C. board according to auxiliary code.
Cause of operation
1. Connection error of communication line
between IPDU and I/F P.C. board
2. I/F P.C. board error
3. IPDU P.C. board error
4. External noise
NO
Connect the jumper lead.
YES
Correct connection of connectors.
YES
Replace communication line.
NO
I/F P.C. board error
NO
IPDU P.C. board error
When IPDU (No.1, No.2) and
three fan IPDU do not return communication
NO
Replace fan power supply P.C. board.
Auxiliary code P.C. board to be replaced
01 IPDU1
02 IPDU2
03 IPDU1, 2
04 Fan IPDU
05 IPDU1, fan IPDU
06 IPDU2, fan IPDU
07 IPDU1, 2, fan IPDU, I/F
Check code Check code name
[F01] Indoor TCJ sensor error
NO
Is TCJ sensor connector (CN102: Red)
on indoor P.C. board normally connected?
YES
NO
Are characteristics of TCJ sensor
resistance value normal?
YES
Indoor unit temperature sensor characteristics
See Characteristics-2.
Check indoor main P.C. board.
Defect Replace
Check code Check code name
[F02] Indoor TC2 sensor error
NO
Is TC2 sensor connector (CN101: Black)
on indoor P.C. board normally connected?
YES
NO
Are characteristics of TC2 sensor
resistance value normal?
YES
Indoor unit temperature sensor characteristics
See Characteristics-2.
Check indoor main P.C. board.
Defect Replace
Check code Check code name
[F03] Indoor TC1 sensor error
NO
Is TC1 sensor connector (CN100: Brown)
on indoor P.C. board normally connected?
YES
NO
Are characteristics of TC1 sensor
resistance value normal?
YES
Indoor unit temperature sensor characteristics
See Characteristics-2.
Check indoor main P.C. board.
Defect Replace
Cause of operation
TCJ sensor Open/Short
Correct connection of connector.
Replace TCJ sensor.
Cause of operation
TC2 sensor Open/Short
Correct connection of connector.
Replace TC2 sensor.
Cause of operation
TC1 sensor Open/Short
Correct connection of connector.
Replace TC1 sensor.