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Fujitsu code 94: over current error or trip detection

By How House Works EditorialBased on Fujitsu manualsChecked against sources Updated

Fujitsu display

94

“Over current error (Outdoor unit)”

KPAS, KPBS, KMAS, KZAS · KPAS/KPBS Service Manual SR_AS142ES_09, p. 03-3; KMAS Service Manual SR_AS134ES_03, p. 03-2; KZAS Service Manual SR_AS137ES_03, p. 03-2
Technician

OPERATION 9 / TIMER 4. Set when the compressor makes 10 overcurrent protection stops in a row after its start-up has finished (KPAS/KPBS Service Manual SR_AS142ES_09, p. 03-58). KZAS also has a “Trip detection (Outdoor unit)” line for 94 (see the next row). KPAS installation manual: “Trip detection” (KPAS Installation Manual, p. En-16).

What it means

Code 94 means the outdoor unit has stopped the compressor for overcurrent several times in a row. In the installation manuals’ lamp tables it is nine OPERATION blinks and four TIMER blinks, repeated, while ECONOMY blinks fast KPAS Installation Manual, p. En-16; LZBS Installation Manual, p. En-11; RLS3 Installation Manual, p. En-12.

The KPAS/KPBS service manual sets it when the protection stop “by over-current generation after inverter compressor start processing completed” happens 10 times in a row; the count resets when the compressor starts up. The causes listed are an outdoor fan that does not run properly, foreign matter on the heat exchanger or a large rise in ambient temperature; a failed main PCB; and a failed inverter compressor, locked or with a winding short KPAS/KPBS Service Manual SR_AS142ES_09, p. 03-58. In that manual’s mobile app table the code is 94.1, “Outdoor unit trip detection” KPAS/KPBS Service Manual SR_AS142ES_09, p. 03-9.

The same code goes by two names:

  • “Over current error (Outdoor unit)” in the KPAS/KPBS, KMAS and KZAS service manuals KPAS/KPBS Service Manual SR_AS142ES_09, p. 03-3; KMAS Service Manual SR_AS134ES_03, p. 03-2; KZAS Service Manual SR_AS137ES_03, p. 03-2.
  • “Trip detection” in the KTAS, ASLH, KNAS and L-series service manuals KTAS Service Manual SR_AS147ES_04, p. 03-2; ASLH Service Manual SR_AS143ES_03, p. 03-2; KNAS Service Manual SR_AS159ES_02, p. 03-3; LZBS Service Manual SR_AS048EF_02, p. 03-2; LZAS Service Manual SR_AS024EF_09, p. 03-2; LMAS Service Manual SR_AS058EF_04, p. 03-2; LPAS Service Manual SR_AS050EF_03, p. 03-2, in the K and L installation manual lists KPAS Installation Manual, p. En-16; LZBS Installation Manual, p. En-11 and in the RLS3-era tables RLS3 Service Manual, p. 7; RL2 Service Manual, p. 12.

The KZAS manual prints both. Its “Trip detection” section names the inverter PCB as the detecting part and its “Over current error” section names the main PCB KZAS Service Manual SR_AS137ES_03, pp. 03-54–03-55. The table in the RLS3 Service Instructions calls it “Over Current Error” p. 02-01, and its check section prints the same count of 10 RLS3 Service Instructions, p. 02-20.

Check these first

Fujitsu’s owner’s manuals give no owner fix for this code. The steps are the same as for any code; the manuals’ wording is on the code 11 page.

  1. Check that it is an error code: OPERATION and TIMER blink while ECONOMY blinks fast KPAS Operation Manual, p. En-13.
  2. Read the code with Service check if your remote has it KPAS Operation Manual, pp. En-13–En-14.
  3. Stop the unit, turn off its breaker and consult authorized service personnel, as the manuals require for this lamp pattern RLS3 Operation Manual, p. En-10; KPAS Operation Manual, p. En-12. This is separate from their rule against using the breaker for everyday on and off KPAS Operation Manual, p. En-2.
  4. Give them the code KPAS Operation Manual, p. En-14.

When to call a licensed technician

The KPAS/KPBS service manual’s checks for 94, in order KPAS/KPBS Service Manual SR_AS142ES_09, p. 03-58:

  • The outdoor unit: obstructions in the air passages, clogged heat exchange fins, the outdoor fan motor, other heat sources raising the ambient temperature, and discharged air being drawn back in.
  • If that does not improve the symptom, replace the main PCB.
  • If that does not help either, replace the compressor.

On KZAS units the “Trip detection” section adds the inverter PCB before the main PCB KZAS Service Manual SR_AS137ES_03, p. 03-54.

Fujitsu’s service manual says anyone working on or breaking into a refrigerant circuit should hold a valid certificate KPAS/KPBS Service Manual SR_AS142ES_09, p. 02-1; in the US, refrigerant work is for a technician certified under EPA Section 608. Fujitsu also warns of electric shock and sets a waiting time after power-off before electrical components are touched: 5 minutes in the service manual, 10 minutes in the KPAS installation manual KPAS/KPBS Service Manual SR_AS142ES_09, p. 02-1; KPAS Installation Manual, p. En-2.

Notes for different models

  • Sections for 94 in the other K-series and L-series service manuals: KNAS Service Manual SR_AS159ES_02, pp. 03-51–03-52; KMAS Service Manual SR_AS134ES_03, p. 03-49; KTAS Service Manual SR_AS147ES_04, p. 03-54; ASLH Service Manual SR_AS143ES_03, p. 03-43; LZBS Service Manual SR_AS048EF_02, p. 03-32; LZAS Service Manual SR_AS024EF_09, p. 03-32; LMAS Service Manual SR_AS058EF_04, p. 03-20; LPAS Service Manual SR_AS050EF_03, p. 03-22. The KMAS, KZAS, KTAS, ASLH and L-series sections print the same count of 10 stops in a row.
  • RLS3-era service instructions with a section for 94: RLS3Y Service Instruction, p. 02-25; RLB Service Instructions, p. 02-19; RLS2 Service Instructions, p. 02-20; RLFW1 Service Instruction, p. 02-18. They print the same count of 10.

Related Fujitsu codes

  • 95 “Compressor motor control error (Outdoor unit)”
  • 65 “IPM error (Outdoor unit)”
  • 97 “Outdoor unit fan motor error (Outdoor unit)”

See also

Other ductless mini-splits: Daikin, Mitsubishi Electric, MrCool

All Fujitsu codes

Fujitsu is a trademark of its owner. How House Works is not affiliated with or endorsed by Fujitsu.

Sources

  1. GENERAL Inc.. KPAS/KPBS Service Manual SR_AS142ES_09. Document code SR_AS142ES_09, page stamp 2026.06.18; covers ASUH09–36KPAS/KPBS and AOUH09–36KPAS1. The 2026 revision. It adds code 45, which the earlier revision SR_AS142ES_04 does not list.. Accessed Oct 12, 2026.
  2. Fujitsu General America / GENERAL HVAC Solutions America (document portal). KPAS Installation Manual. PART No. 9387603408-01; KP series; no publication date printed. Accessed Oct 12, 2026.
  3. Fujitsu General America / GENERAL HVAC Solutions America (document portal). KPAS Operation Manual. PART No. 9387602548-01; KP series; no publication date printed. Accessed Oct 12, 2026.
  4. Fujitsu General Limited. KNAS Service Manual SR_AS159ES_02. Document code SR_AS159ES_02, page stamp 2025.10.08; covers ASUH09–24KNAS and AOUH09–24KNAS1. Accessed Oct 12, 2026.
  5. Fujitsu General Limited. KMAS Service Manual SR_AS134ES_03. Document code SR_AS134ES_03, page stamp 2024.11.11; covers ASUH09/12KMAS and AOUH09/12KMAS1. Accessed Oct 12, 2026.
  6. Fujitsu General Limited. KZAS Service Manual SR_AS137ES_03. Document code SR_AS137ES_03, page stamp 2025.01.09; covers ASUH09–24KZAS and AOUH09–24KZAH1. Accessed Oct 12, 2026.
  7. Fujitsu General Limited. KTAS Service Manual SR_AS147ES_04. Document code SR_AS147ES_04, page stamp 2025.07.30; titled Service Manual for Cold Climate Region; covers ASUH09/12/15KTAS and KTAB with AOUH09/12/15KTAP1. Accessed Oct 12, 2026.
  8. Fujitsu General Limited. ASLH Service Manual SR_AS143ES_03. Document code SR_AS143ES_03, page stamp 2024.11.11; covers ASLH09/12KNAS and AOLH09/12KNAS1, 115 V. Its code table prints blink counts only, with no wired remote controller code column.. Accessed Oct 12, 2026.
  9. Fujitsu General Limited. LZBS Service Manual SR_AS048EF_02. Document code SR_AS048EF_02, page stamp 2022.10.14; covers ASUG09–15LZBS and AOUG09–15LZAS1. Accessed Oct 12, 2026.
  10. Fujitsu General America / GENERAL HVAC Solutions America (document portal). LZBS Installation Manual. PART No. 9387603187; no publication date printed. Accessed Oct 12, 2026.
  11. Fujitsu General Limited. LZAS Service Manual SR_AS024EF_09. Document code SR_AS024EF_09, page stamp 2022.10.12; covers ASUG09–15LZAS and AOUG09–15LZAS1. Accessed Oct 12, 2026.
  12. Fujitsu General Limited. LMAS Service Manual SR_AS058EF_04. Document code SR_AS058EF_04, page stamp 2022.10.05; covers ASUH09/12LMAS and AOUH09/12LMAS1. Accessed Oct 12, 2026.
  13. Fujitsu General Limited. LPAS Service Manual SR_AS050EF_03. Document code SR_AS050EF_03, page stamp 2022.10.18; covers ASUH09/12LPAS and AOUH09/12LPAS1. Accessed Oct 12, 2026.
  14. Fujitsu General America / GENERAL HVAC Solutions America (document portal). RLS3 Service Manual. No document code printed; the error table page is stamped 2015.01.06; covers ASU9/12RLS3 and AOU9/12RLS3. Accessed Oct 12, 2026.
  15. Fujitsu General America / GENERAL HVAC Solutions America (document portal). RLS3 Service Instructions. No document code or date printed; covers ASU9/12/15RLS3 and AOU9/12/15RLS3. Accessed Oct 12, 2026.
  16. Fujitsu General America / GENERAL HVAC Solutions America (document portal). RLS3 Installation Manual. PART No. 9320456016; no publication date printed. Accessed Oct 12, 2026.
  17. Fujitsu General America / GENERAL HVAC Solutions America (document portal). RLS3 Operation Manual. PART No. 9320455026; no publication date printed. Accessed Oct 12, 2026.
  18. Fujitsu General America / GENERAL HVAC Solutions America (document portal). RLS3Y Service Instruction. No document code or date printed; covers ASU9/12/15RLS3Y and AOU9/12/15RLS3. The cover is stamped “TENTATIVE”.. Accessed Oct 12, 2026.
  19. Fujitsu General America / GENERAL HVAC Solutions America (document portal). RLB Service Instructions. No document code or date printed; covers ASU18/24RLB and AOU18/24RLB. Accessed Oct 12, 2026.
  20. Fujitsu General America / GENERAL HVAC Solutions America (document portal). RLS2 Service Instructions. No document code or date printed; covers ASU9/12/15RLS2 and AOU9/12/15RLS2. Accessed Oct 12, 2026.
  21. Fujitsu General America / GENERAL HVAC Solutions America (document portal). RLFW1 Service Instruction. No document code or date printed; covers ASU9/12RLF1 and AOU9/12RLFW1. Accessed Oct 12, 2026.
  22. Fujitsu General America / GENERAL HVAC Solutions America (document portal). RL2 Service Manual. No document code printed; the error table page is stamped 2012.11.07; covers ASU9/12RL2 and AOU9/12RL2. Its code table prints blink counts only, with no wired remote controller code column.. Accessed Oct 12, 2026.