Er dS Serious Moderate DIY

LG Refrigerator Er dS — Defrost sensor (thermistor) failure

LG Refrigerator · Error code Er dS

What Er dS Means

The defrost thermistor on the evaporator is open, shorted, or out of resistance range — the board can't monitor evaporator temperature during defrost.

Symptoms

  • Er dS on display
  • Eventual frost buildup on back wall of freezer
  • Temps may still appear normal at first
  • Companion Er dH may appear later

Common Causes

1
Open thermistor element

Internal break in the NTC sensor.

2
Shorted sensor wiring

Pinched/damaged harness near the evaporator.

3
Connector corrosion

Moisture in the rear-panel connector.

4
Main board ADC fault

Rare; control board input failed.

How to Fix It

  1. Unplug the refrigerator and remove the freezer rear panel.
  2. Locate the defrost thermistor clipped to the evaporator coil.
  3. Measure resistance and compare to the LG service chart at known temperature.
  4. If open or out of spec, replace the thermistor (cheap and quick).
  5. Reseat and inspect the harness connector for corrosion or pinch damage.
  6. Restore power and verify Er dS clears after one defrost cycle.

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 Defrost thermistor View on Amazon→

More LG Refrigerator Codes

22 22 — Compressor relay / inverter control fault 33 33 — Compressor / defrost test fault 67 67 — Door open / not fully closed 88 88 — Power-on display test (not a fault) Er CF Er CF — Condenser Fan Fault Er CO Er CO — Compressor / Communication Fault

All LG codes → All refrigerator codes →

Verified against manufacturer documentation: lg.com

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