Daikin Mini-Split Code J5
Warning
Suction pipe thermistor (R3T, R5T) abnormality. A short or open circuit was detected in the suction line temperature sensor.
Manual wording: “J5 Suction pipe thermistor (R3T, R5T) abnormality”
Documented for: RMXS multi-split outdoor units
Likely causes, most common first
- Disconnection of thermistor
- Defective suction pipe thermistor (R3T, R5T)
- 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
A technician must identify which of the two suction thermistors failed using the outdoor unit's monitor mode.
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