Skip to main contentStart diagnosing P4 on your Daikin air conditioner
Daikin Air Conditioner Error Code P4
P4Daikin Air Conditioner
What this code means
Radiation fin thermistor abnormality - open or short circuit detected during compressor stop.
First step from the service manual
Disconnect connector X111A on inverter PCB and check thermistor resistance at room temperature.
Next steps: diagnose the root cause
1
Verify the error code is active
Power cycle the unit and see if the code returns. If it does, the fault is persistent and requires diagnosis.
2
Get the full diagnostic procedure
Get step-by-step guidance, test values, and wiring diagrams from the OEM service manual.
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What’s available for Daikin air conditioner models
Access Daikin air conditioner service manuals, wiring schematics, exploded parts views, and error code references on MyPros+.