Outdoor unit does not start or stops shortly after starting, indoor unit shows E3

Safety: Turn off the dedicated AC breaker before opening any electrical covers. Verify power is off with a tester.

Steps:

• Check power supply: Confirm the outdoor unit has correct voltage at its terminals according to the rating plate.
• Inspect communication cable: On Electrolux split systems, terminals are usually labeled L, N, and S (signal) or 1, 2, 3. Ensure wires are firmly secured and match exactly between indoor and outdoor units (same color to same terminal).
• Check polarity: If the system uses line/neutral-specific terminals, verify they are not reversed. Correct any miswiring.
• Look for damage: Trace the interconnecting cable for cuts, rodent damage, or crushed sections. Replace the cable if insulation is damaged or conductors are exposed.
• Reseat connectors: At both indoor and outdoor PCBs, reseat the communication harness connectors.
• Board diagnosis: If wiring is correct and intact, but E3 persists, the communication circuit on either the indoor or outdoor PCB may be defective. This typically requires board replacement and should be done by a qualified technician.