Daikin REYQ-AATJA, Service Manual, Page: 393 / 495

SiUS372201EA Troubleshooting by Error Code
Part 6 Service Diagnosis 386
3.61 Inverter Radiation Fin Temperature Abnormality
3.61.1 Inverter Radiation Fin Temperature Abnormality (Inverter PCB)
Applicable
Models
All outdoor unit models
Error Code
P4
Sub code: 09-13
Method of Error
Detection
Detect the resistance of the following thermistors while the compressor is not running:
 Radiation fin thermistor
 Thermistor located in PCB circuit
 Heat sink thermistor
Error Decision
Conditions When the resistance of the thermistor comes to a value equivalent to open or short circuit.
Error is not decided while the unit operation is continued.
P4 will be displayed by pressing the inspection button.
Supposed
Causes
 Defective radiation fin temperature thermistor
 Defective inverter PCB

Defective compressor
 Defective fan motor
Troubleshooting
Make measurement of
resistance of the radiation fin
thermistor.
Is the
resistance of the
relevant thermistor
normal?
The
insulation
resistance of the
relevant compressor is not
more than 100 k .
The insulation
resistance of the relevant
fan motor is not more
than 1 M .
Turn ON
the power supply.
Does the error
recur?
NO
YES
NO
YES
NO
YES
YES
NO
Replace the inverter PCB.
Replace the compressor.
Replace the fan motor
(M1F, M2F).
Replace the inverter PCB.
Continue operation.
Caution
Be sure to turn off the power switch before connecting or disconnecting
connectors, or parts may be damaged.