Fujitsu Mini-Split Code 44
WarningShown as: OPERATION lamp blinks 4 times, TIMER lamp blinks 4 times, ECONOMY lamp blinking continuously
Human sensor error. The occupancy (human) sensor on the indoor unit is not responding correctly to the control board.
Manual wording: “Human Sensor error - Check if the connector connection and if cable is open”
Documented for: RGLX indoor units fitted with the human/occupancy sensor option
Likely causes, most common first
- Loose or removed human sensor connector
- Erroneous connection at the sensor plug
- Open sensor cable
- Failed sensor, or failed main PCB
What you can safely check yourself
- Turn the power off at the breaker for about 5 minutes and back on to see whether the code clears
When to call a technician
Diagnosing this requires continuity and 5 VDC checks at connector CN67 on the main board. That is technician work.
A Fujitsu mini-split throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.
Source
- 410A Mini-Split Troubleshooting Guide (Part # 6-26-FG2020 Rev. 5/2019) (Fujitsu General America, Inc., All R410A Halcyon mini-splits: RGLX, RL2/RLS3/RLS3H/RLS3Y/RLB/RLXB/RLXEH wall mounted, RLF/RLF1 multi-zone indoor units, RLXFZ multi-zone outdoor units, RML/RMLQ, RULX/RSLX universal-mount, RCLX cassettes) · checked 2026-08-25