Daikin REYQ-AATJA, Service Manual, Page: 389 / 495

SiUS372201EA Troubleshooting by Error Code
Part 6 Service Diagnosis 382
3.59 Transmission Error between Inverter PCB and Outdoor
Unit Main PCB
Applicable
Models
All outdoor unit models
Error Code
LC
Method of Error
Detection
Check for the transmission conditions between the inverter PCB and the outdoor unit main PCB
using a microcomputer.
Error Decision
Conditions
When normal transmission is disabled for a given period of time or more.
Supposed
Causes
 Defective connection between the inverter PCB and the outdoor unit main PCB

Defective outdoor unit main PCB (transmission block)
 Defective noise filter, compressor or fan motor
 External factors (e.g. noise)
 Failure of inverter PCB or fan PCB
Troubleshooting
Does the
inverter PCB part
No. match that of the spare
parts list?
Replace with a proper PCB.
NO
Properly connect the connector.
NO
YES
Replace the fan motor.
YES
NO
The insulation
resistance of the
relevant compressor is
less than 100 k .
The
insulation
resistance of the relevant
fan motor is less than
1 M
Replace the compressor.
YES
NO
YES
Caution
Be sure to turn off the power switch before connecting or disconnecting
connectors, or parts may be damaged.
Is the
connector
between each outdoor
unit main PCB and each
inverter PCB securely
connected?
( 1)
A
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