ErrorCodeDoctor
Daikin · Air Conditioner

Daikin Air Conditioner AJ error code

Difficulty: Hard · Cost: $80–$250 · Duration: Requires professional service

The AJ error means your Daikin air conditioner detected a capacity setting fault. This typically occurs after an indoor unit PCB has been replaced without installing the capacity setting adaptor, or the PCB itself is defective. Contact a qualified technician to install the correct capacity setting adaptor.

Common causes

  • Capacity setting adaptor was not installed after replacing the PCB
  • Defective indoor unit PCB

How to fix it

  1. 1

    Contact a qualified technician to install the correct capacity setting adaptor or inspect the PCB

Related Daikin Air Conditioner error codes

1

A0

An external protection device connected to the indoor unit has been activated

hard
2

A1

A fault was detected in the indoor unit PCB (control board)

hard
3

A3

The drain level control system has detected an abnormality — drain may be clogged

medium
4

A5

Freeze-up protection (cooling) or high pressure control (heating) has activated — check the air filter

easy