Fujitsu Mini-Split Code 84
Soft lockoutShown as: OPERATION lamp blinks 8 times, TIMER lamp blinks 4 times, ECONOMY lamp blinking continuously
Current sensor error. The input current sensor read 0 amps while the inverter compressor was running above 56 rps, one minute after start-up (outside of defrost).
Manual wording: “Current Sensor Error - When input current sensor has detected 0A, while the inverter compressor is operating at higher than 56rps, after 1 minute upon starting the compressor.”
Documented for: RGLX, RL2/RLS3/RLB/RLXB, RLF/RLF1 outdoor units
Likely causes, most common first
- Loose terminal connection at the outdoor unit
- Connector removed from the current transformer
- Erroneous connection
- Failed current sensor or main PCB
What you can safely check yourself
- Turn the power off at the outdoor disconnect and breaker for about 5 minutes, then restore power
When to call a technician
The current sensor wraps the compressor supply conductor inside the electrical box. Only a licensed technician should open that.
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