Fujitsu · Heat pump

16 Peripheral unit / transmission PCB connection error

Medium severity Fujitsu ductless split/multi/VRF (general code list)Fujitsu slim duct ARU 7-18 (LL type)

What the control is telling you

A peripheral or transmission PCB (option kit) is not connecting to the indoor board. Indoor lamps: OPERATION (green) flashes 1x, TIMER (orange) flashes 6x, ECONOMY (green) flashes fast nonstop; wired remote shows 16.

Applies to: Fujitsu ductless heat pumps: Fujitsu ductless split/multi/VRF (general code list), Fujitsu slim duct ARU 7-18 (LL type)

Likely causes

Option PCB plug loose
Option kit fault
Indoor PCB fault

Test and repair steps

Check option kit cables at the indoor board (e.g. CN65 / CN47).
Remove and refit the kit; replace it if the error stays.
Replace the indoor main PCB as a last step.

Settings for these units

Operating range and service space · Fujitsu multi-zone outdoor 18/24 type

Other codes on the same units

11 Serial communication error (indoor/outdoor)
12 Wired remote controller communication error
14 Network communication error
15 Check run unfinished / airflow auto-adjust error
18 External communication error (WLAN / option adapter)
21 Address / refrigerant circuit setting error
22 Indoor unit capacity error
23 Combination error

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Source: Fujitsu All Fujitsu split - multi - VRF (generic code list) codes.pdf - section error code table (indoor LED flashes); Fujitsu Slim duct AR07-09-12-14-18 (ARU-ARYG LL-type equivalent) installation P-N 9381858064.pdf - section 14 Error codes. Summarized in our own words; check the original manual for your model.

Homeowner looking at this code? See what it means for you and when to call a technician.

For licensed technicians. Gas, electrical and refrigerant work must be done by a qualified, licensed person. Shut off power and gas before servicing, never bypass a safety control, and follow the manufacturer’s manual for the exact model; it and local codes always take priority. HVACopedia is not affiliated with any manufacturer; brand and model names only identify the equipment.