Troubleshooting by Error Code
SiME332106E
252
Part 6 Service Diagnosis
5.58 Transmission Error between Indoor Units and Outdoor
Units
Applicable
Models
All indoor unit models
All outdoor unit models
Error Code
U4
Method of Error
Detection
Microcomputer checks if transmission between indoor and outdoor units is normal.
Error Decision
Conditions
Transmission is not carried out normally for a certain amount of time.
Supposed
Causes
Short circuit in indoor-outdoor transmission wiring (F1/F2), or wrong wiring
Outdoor unit power supply is OFF
System address does not match
Defective indoor unit PCB
Defective outdoor unit main PCB