Fujitsu ARU9RLF Service Instruction page 30

Trouble shooting 2
INDOOR UNIT Error Method:
Wired remote controller
communication error
Detective Actuators:
Indoor unit Controller PCB
Wired remote control
Forecast of Cause:
1. Terminal connection abnormal
Check Point 1 : Check the connection of terminal
After turning off the power, check & correct the followings.
Check the connection of terminal between remote control and Indoor unit,
and check if there is a disconnection of the cable.
OK OK
Check Point 2 : Check Remote Control and Controller PCB
Check Voltage at CN14 (terminal 1-3) of Controller PCB. (Power supply to Remote Control)
>> If it is DC13V, Remote Control is failure. (Controller PCB is normal)
>> If it is DC 0V, Controller PCB is failure. (Check Remote Control once again) >> Replace Controller PCB
Upon correcting the removed connector or mis-wiring, reset the power.
Indicate or Display:
Refer to error code table.
Detective details:
When the indoor unit cannot receive the signal from Wired Remote Control
more than 1minute during normal operation.
2. Wired remote control failure
02-05
3. Controller PCB failure
>> Replace Remote Control