3 SY Moderate Moderate DIY

Frigidaire Refrigerator 3 SY — Evaporator Sensor Open

Frigidaire Refrigerator · Error code 3 SY

What 3 SY Means

Open-circuit reading on the evaporator thermistor. Board cannot verify coil temperature during defrost.

Symptoms

  • 3 SY shown
  • Excessive frost on evaporator
  • Long defrost cycles or repeated defrost
  • Warm freezer compartment

Common Causes

1
Open evaporator thermistor

Element broken.

2
Severed sensor wire

Cut by defrost ice or sharp panel edge.

3
Loose connector

Disconnected at the main board.

How to Fix It

  1. Unplug refrigerator and access the freezer evaporator coil.
  2. Inspect and reseat sensor connector.
  3. Ohm sensor — replace if open.
  4. Check wiring continuity back to the main board.
  5. Replace main board if input is dead.

Parts You May Need

If diagnosis points to a failed part, these are the common replacements. As an Amazon Associate we earn from qualifying purchases.

Common replacement Evaporator thermistor View on Amazon→

More Frigidaire Refrigerator Codes

1F 1F — Ice Maker Fault 1 SH 1 SH — Fresh Food Sensor Shorted 1 SY 1 SY — Fresh Food Sensor Open 2 SH 2 SH — Freezer Sensor Shorted 3 SH 3 SH — Evaporator Sensor Shorted 4 SY 4 SY — Ambient / Defrost Sensor Open

All Frigidaire codes → All refrigerator codes →

Verified against manufacturer documentation: frigidaire.com

Always unplug an appliance before servicing it. This guide is for informational purposes and is not a substitute for a qualified technician.