Sub-Zero Refrigerator Error Code t2: Thermistor 2... | appliancefaults.com

Technical Background:

The Sub-Zero control board monitors the resistance of thermistor 2 to determine the refrigerator compartment temperature. The MCU (Microcontroller Unit) within the control board interprets the voltage drop across the thermistor. If the resistance falls outside of the acceptable range, the control board triggers error code t2. This voltage is typically a 5V DC signal that gets pulled low through the thermistor to ground.

Symptoms:

The Sub-Zero refrigerator displays error code t2. The refrigerator compartment may not be maintaining the correct temperature. You might notice unusually warm food or frost accumulation.

Possible Causes:

Open or shorted thermistor 2
Wiring harness issue between the thermistor and the control board
Loose connection at the thermistor or control board
Defective control board
Thermistor located in an area with extreme temperature variations
Ice build-up on the thermistor

Solution:

1

Disconnect power to the Sub-Zero refrigerator at the breaker panel.
2

Locate thermistor 2 within the refrigerator compartment, typically near the evaporator coil.
3

Using a multimeter, measure the resistance of thermistor
4

Compare the reading to the Sub-Zero service manual’s temperature/resistance chart. A significantly different reading indicates a faulty thermistor.
5

Inspect the wiring harness and connections leading to thermistor 2 and the control board for any signs of damage or loose connections. Repair or replace as needed.
6

If the wiring and thermistor appear to be in good condition, access the control board. With the unit unplugged, visually inspect the board for burned components or damaged traces. If damage is evident, replace the control board.
7

If the thermistor tests bad, replace it with a new, OEM Sub-Zero thermistor.
8

Reconnect power and monitor the refrigerator's operation. If the error code persists after replacing the thermistor, the control board is likely the cause.

Safety Warning:

Disconnect power to the appliance before performing any repairs. Use Lock-Out/Tag-Out (LOTO) procedures to prevent accidental power restoration. Exercise caution when working with electrical components. Some components may retain a high voltage charge even after the appliance is unplugged.

Prevention:

Regularly inspect the refrigerator compartment for ice build-up and defrost as needed. Ensure proper door sealing to prevent excessive temperature fluctuations. Clean the condenser coils every 6 months to ensure efficient operation.

Expert Tip:

Many Sub-Zero models have a diagnostic mode. Refer to the service manual to access this mode. This will allow you to view real-time thermistor readings and run diagnostic tests without fully disassembling the unit. This may also allow you to clear the error code after replacing the thermistor.

Frequently Asked Questions

•What is the typical resistance range for thermistor 2 at 35 degrees Fahrenheit?

Refer to the Sub-Zero service manual for the specific resistance range for thermistor 2 at 35 degrees Fahrenheit. However, generally, it's usually between 8k and 12k Ohms.

•Where is the control board located in my Sub-Zero refrigerator?

The control board location varies depending on the model. Typically, it's located behind a panel at the top of the refrigerator, either in the front or the rear. Consult the service manual for your specific model.

•Can I use an aftermarket thermistor, or do I need a genuine Sub-Zero part?

It is highly recommended to use a genuine OEM Sub-Zero thermistor. Aftermarket thermistors may have different resistance curves, which can cause inaccurate temperature readings and improper operation.

Sub-Zero Refrigerator Error Code t2: Thermistor 2 Troubleshooting Guide

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•What is the typical resistance range for thermistor 2 at 35 degrees Fahrenheit?

•Where is the control board located in my Sub-Zero refrigerator?

•Can I use an aftermarket thermistor, or do I need a genuine Sub-Zero part?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: