SubZero Refrigerator Freezer Error Code 05 – How to fix? by KatyApplianceRepair.com 

Sub-Zero error code EC 05 indicates
a refrigerator thermistor fault. Below is a quick reference
and troubleshooting guide for this code.

Quick Reference

Error Code	Meaning	Severity
EC 05	Thermistor fault — inconsistent temperature readings in the refrigerator cabinet	Medium

Cause & Solution

Cause	What to Check	Fix
Loose or faulty thermistor wiring	Inspect connections between the thermistor and control board at J5	Reconnect or repair wiring; check continuity with a multimeter
Defective thermistor	Measure resistance — should read 30,000–33,000 ohms at 32 °F (0 °C)	Replace the thermistor if readings are out of range