Daikin Mini-Split Code JA
Warning
High pressure sensor abnormality. The outdoor unit's high-side pressure transducer is reading out of range.
Manual wording: “JA High pressure sensor abnormality”
Documented for: RMXS multi-split outdoor units
Likely causes, most common first
- Disconnection of the high pressure sensor connector
- Defective high pressure sensor
- Defective main PCB (A1P)
What you can safely check yourself
- Turn the system off at the breaker or disconnect switch and back on once
When to call a technician
The pressure sensor is part of the sealed refrigerant circuit and must be diagnosed and replaced by a technician.
A Daikin mini-split throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.
Source
- Service Manual - Multi-Split Type Air Conditioners RMXS-L Series (SiUS181631EA) (Daikin, RMXS48LVJU outdoor, BPMKS048A2U/049A3U branch provider, CTXG/CTXS/FTXS/CDXS/FDXS/FVXS/FFQ indoor units) · checked 2026-08-25