Service Manual

SiUS281811E Troubleshooting by Error Codes
Part 6 Service Diagnosis 237
4.40 Radiation Fin Temperature Rise Abnormality
Error Code L4
Applicable
Models
All outdoor units
Method of Error
Detection
The radiation fin temperature is detected by the radiation fin thermistor.
Error Decision
Conditions
The radiation fin temperature exceeds a certain temperature.
Supposed
Causes
 Activation of radiation fin thermistor
 Defective outdoor main PCB
 Defective radiation fin thermistor
Troubleshooting
Defective radiation from the power
unit
• Blocked air suction port
• Stained radiation fin
• High outdoor air temperature
Connect correctly.
Go to P4 troubleshooting.
Keep operating.
Replace the outdoor main
PCB (A1P).
Be sure to turn off the power switch before connecting or disconnecting
connectors, or parts may be damaged.
Caution
YES
YES
YES
YES
NO
NO
NO
NO
Is the radiator fin
temperature greater than the
designed temperature?
Does the remote
controller display error code
P4?
Does the
connector X111A of fin
thermistor connect to the
outdoor unit PCB
correctly?
When the unit starts
operating, is the error code L4
displayed again?
Connect to the power.