Fujitsu AUUH18LUAS Service Manual page 85

2-13. E: 3A.X. Indoor unit communication circuit (wired remote
controller) error
→ired remote
Indicator
controller
→ired remote controller (2-wire)
Detective actuator
Indoor unit controller PCB circuit
Forecast of cause
Check point 1. Check the connection of terminal
• After turning off the power supply, check and correct the followings
Indoor unit - Check the connection the communication PCB and the main PCB
Check Point 2 : Replace the communication PCB
If the Check point 1 is ok, replace the communication PCB
Check Point 3 : Replace the main PCB
If condition is doesn't change, replace the main PCB
2-13. E: 3A.↓. Indoor unit communication circuit (wired remote controller) error
Error code
End
Detect the communication error of microcomputer and
communication PCB.
Communication PCB defective
Indoor unit main PCB defective
- (03-19) -
E: 3A
2. Troubleshooting with error code