AUX AC Error Codes: What They Mean & What to Do

AUX publishes an official error-code list, which puts it ahead of most value brands — but its own regional sites disagree on E3 and E4, so those two codes are published as conflicts rather than resolved. AUX is also the manufacturing platform behind certain Electrolux-branded units, and AUX's own documentation provides a code translation table between the two. That translation is a mapping, not a merge: the same label can mean different faults on each brand.

Product families covered

• Split / inverter / Freedom T1

  The official AUX global E / F / P code list.

• Wired-controller commercial / ducted

  Dual display convention — display board code and wired controller code for one fault.

Where the code is displayed — and why it matters

The same fault can be labelled differently depending on which display you read it from, so identify the display before looking the code up.

Indoor unit display

Splits show the E, F or P code on the front panel.

Unit display board (ducted)

Shows codes such as L1, L3 and P2.

Wired room controller (ducted)

Shows the same faults as C1, C3 and J2 — a different label for one fault.

AUX code prefixes

The prefix narrows the fault area:

E

Indoor-side, sensor, memory and communication faults

F

Outdoor unit — fan, module, PFC, compressor start, sensors, EEPROM

P

Protections — pressure, refrigerant, overload, discharge temperature

L / C / H / J

Ducted range: display-board and wired-controller labels for the same faults

How the families differ

• On the ducted range the same fault carries two labels depending on where you read it — a display-board number and a controller letter code — so both readings should be recorded.
• AUX's own regional documentation disagrees on E3 and E4, which is a same-brand, same-code discrepancy rather than a third-party error.
• Electrolux units built on the AUX platform use different labels for the same faults, and one label (E4) means different things on each brand.
• AUX VRF-specific codes were not surfaced in our research and are not published here.

AUX split / inverter / Freedom T1 codes

From the official AUX Global error-code pages and the official 2021 AUX troubleshooting PDF. Severity is not given per code in our AUX sources, so no severity level is published.

AUX ducted range — display board and wired controller codes

From a strong secondary compilation documenting the dual-display convention. The controller label for each fault is noted on the row.

AUX ↔ Electrolux code translation

AUX manufactures the control platform behind certain Electrolux-branded units, and AUX's own documentation supplies this cross-reference. Read it as a translation table, never a merge — AUX E4 is a fan/motor fault while Electrolux E4 is a communication fault, so the labels are not interchangeable.

Internal (room) temperature sensor error

E1 — AS

Internal coil sensor error

E3 — ES

Lower DC motor error

E4 — L3

Communication failure, display board ↔ main control panel

E8 — E4

Water full alarm

P1 — P1

Before you act on a code

• E3 and E4 are documented differently across two official AUX regional pages. Source confidence: official but conflicting — model-specific verification required.
• F1, F2 and P8 are inverter module, PFC and overcurrent protections: leave the unit off rather than resetting repeatedly.
• Do not read an Electrolux code against the AUX table directly — use the translation, because at least one label means different faults on each brand.
• AUX VRF-specific code tables are still in technical review.

B Corroborated across independent technical sources

How to identify your system

1. Note the exact code and where you read it — indoor display, unit display board or wired room controller.
2. On ducted systems, record both the display-board and controller readings if both are visible.
3. Photograph the indoor unit's model label; it is what resolves the E3 / E4 discrepancy.

No code showing? Start from the symptom

• AC not cooling
• AC leaking water