Sub-Zero ICBIC-24C Troubleshooting

This guide provides detailed troubleshooting steps for various error codes and operational issues encountered with the Sub-Zero ICBIC-24C refrigerator. It covers thermistor conditions, fan testing, and wiring information.

Error Code Troubleshooting Guide

Code	Severity	Description and Action	Code	Severity	Description and Action
10 0 00	2	Condenser thermistor open. Verify temperature reading and ohm thermistor. Replace thermistor if bad.	10 2 01	2	Zone 2 cabinet thermistor shorted. Verify temperature reading and ohm thermistor. Replace thermistor if bad.
10 0 01	2	Condenser thermistor shorted. Verify temperature reading and ohm thermistor. Replace thermistor if bad.	10 2 02	2	Zone 2 cabinet thermistor unstable. Check for bad connections and/or damaged wires. Repair connection or wire.
10 0 02	2	Condenser thermistor unstable. Check for bad connections and/or damaged wires. Replace thermistor if bad.	10 2 10	2	Zone 2 evaporator thermistor open. Verify temperature reading and ohm thermistor. Replace thermistor if bad.
10 1 00	2	Zone 1 cabinet thermistor open. Verify temperature reading and ohm thermistor. Replace thermistor if bad.	10 2 11	2	Zone 2 evaporator thermistor shorted. Verify temperature reading and ohm thermistor. Replace thermistor if bad.
10 1 01	2	Zone 1 cabinet thermistor shorted. Verify temperature reading and ohm thermistor. Replace thermistor if bad.	10 2 12	2	Zone 2 evaporator thermistor unstable. Check for bad connections and/or damaged wires. Repair connection or wire.
10 1 02	2	Zone 1 cabinet thermistor unstable. Check for bad connections and/or damaged wires. Repair connection or wire.	10 3 00	2	Zone 3 cabinet thermistor open. Verify temperature reading and ohm thermistor. Replace thermistor if bad.
10 1 10	2	Zone 1 evaporator thermistor open. Verify temperature reading and ohm thermistor. Replace thermistor if bad.	10 3 01	2	Zone 3 cabinet thermistor shorted. Verify temperature reading and ohm thermistor. Replace thermistor if bad.
10 1 11	2	Zone 1 evaporator thermistor shorted. Verify temperature reading and ohm thermistor. Replace thermistor if bad.	10 3 02	2	Zone 3 cabinet thermistor unstable. Check for bad connections and/or damaged wires. Repair connection or wire.
10 1 12	2	Zone 1 evaporator thermistor unstable. Check for bad connections and/or damaged wires. Repair connection or wire.	10 3 10	2	Zone 3 evaporator thermistor open. Verify temperature reading and ohm thermistor. Replace thermistor if bad.
10 2 00	2	Zone 2 cabinet thermistor open.	10 3 11	2	Zone 3 evaporator thermistor shorted. Verify temperature reading and ohm thermistor. Replace thermistor if bad.
15 3 01	5	Zone 3 compressor relay stuck closed. Verify and replace control board.	15 4 00	2	Defrost relay stuck open. No power to defrost heater; verify and replace control board.
15 4 01	3	Defrost relay stuck closed. Verify and replace control board.	15 C 00	1	AC condenser fan relay stuck open. No power to condenser fan; verify and replace control board.
15 C 01	1	AC condenser fan relay stuck closed. Verify and replace control board.	15 U 00	1	Water valve no current detected. No current change detected for activated call for water or dispense; possible stuck open relay or failed valve.
15 U 01	4	Water valve current detected. After valid dispense or ice maker fill, current is still detected for a water call. Check for shorted relay on control board; replace control board.	20 2 00	2	Defrost bi-metal stuck open. Verify the bi-metal is an open circuit below -2° C; replace defrost bi-metal if necessary.
20 2 01	2	Defrost bi-metal stuck closed. Verify the bi-metal is closed above 28° C; replace defrost bi-metal if necessary.	20 2 05	1	Defrost bi-metal mis-wire with normal temperatures. Normal defrost temps, but inappropriate response from bi-metal. Check wiring and bi-metal mounting; correct any issue found.
20 2 06	2	Defrost bi-metal mis-wire with overheating. High temps during defrost and inappropriate response from bi-metal. Check wiring and bi-metal mounting; correct any issue found.	20 2 50	2	Defrost heater open. Check defrost heater ohms. Verify wiring and heater; replace heater if necessary.
30 8 05	1	No signal from ice maker for fill. Check wiring and power to ice maker.	35 1 00	2	Zone 1 evaporator fan open. Check control board, door/drawer switch, and evaporator fan; replace failed part.
35 1 33	1	Zone 1 fan speed faster than setting. Verify fan is not shorted; the fan is running faster than its setting. Possible control board reading error, evaporator fan error, or wiring/connector error; replace faulty part.	35 1 34	1	Zone 1 fan speed slower than setting. Check fan for obstructions, wiring issues, and actual voltage from control board; replace faulty part.
35 2 00	2	Zone 2 evaporator fan open. Check control board and evaporator fan; replace faulty part.	35 2 33	1	Zone 2 fan speed faster than setting. Verify fan not shorted; the fan is running faster than its setting. Possible control board reading error, evaporator fan error, or wiring/connector error; replace faulty part.
35 2 34	1	Zone 2 fan speed slower than setting. Check fan for obstructions, wiring issues, and actual voltage from control board; replace faulty part.	35 3 00	2	Zone 3 evaporator fan open. Check control board and evaporator fan; replace faulty part.
35 3 33	1	Zone 3 fan speed faster than setting. Verify fan not shorted; the fan is running faster than its setting.	35 3 34	1	Zone 3 fan speed slower than setting. Check fan for obstructions, wiring issues, and actual voltage from control board; replace faulty part.
35 A 00	1	Air filter fan open. Check control board and air filter fan; replace faulty part.	35 C 00	1	DC condenser fan open. Check wiring and power to condenser fan; replace faulty part.
35 C 33	1	DC condenser fan speed faster than setting. Verify fan not shorted; the fan is running faster than its setting. Possible control board reading error, condenser fan error, or wiring/connector error; replace faulty part.	35 C 34	1	DC condenser fan speed slower than setting.
40 1 00	1	Zone 1 stepper current fault. No current detected.	45 1 00	1	Check baffle operation; replace baffle or control board.
40 1 40	3	Zone 1 excessive compressor runtime. Verify performance of unit and check for door leaks, door ajar, proper charge in system, and icing of evaporator; replace faulty part.	45 1 01	1	Lights open circuit. Main lights relay open, bulb open, or circuit open; repair circuit or replace bulb or control board.
40 1 87	1	Zone 1 stepper cooling fault. No cooling detected.	45 2 00	1	Lights short circuit. Main lights relay closed, bulb or circuit damage; repair or replace damaged part.
40 2 00	1	Zone 2 stepper current fault. No current detected.	45 2 01	1	Lights open circuit. Main lights relay open, bulb open, or circuit open; repair or replace damaged part.
40 2 40	3	Zone 2 excessive runtime. Verify performance of unit and check for door leaks, door ajar, proper charge in system, and icing of evaporator; replace faulty part.	90 5 80	1	Lights short circuit. Main lights relay closed, bulb or circuit damage; repair or replace damaged part.
40 2 87	1	Zone 2 stepper cooling fault. No cooling detected.	90 Η 80	2	No UIM communications. Check wiring and key performance of UIM; replace or repair failed part.
40 3 40	3	Zone 3 excessive runtime. Verify performance of unit and check for door leaks, door ajar, proper charge in system, and icing of evaporator; replace faulty part.	90 Η 82	1	High voltage micro (CCM) no communication. Communication problems on control board; replace control board.
40 9 40	1	Dispenser active for maximum fill time. Verify no stuck keys or flooding. Reset after 30 days; allows service time to review any issues that occurred/usage.	90 Η 83	2	High voltage micro (CCM) partial communication. Intermittent communications on control board, check harnesses and connections; replace harness or control board.
40 b 00	1	Baffle current fault. Check harness and power from control board; repair harness or replace baffle or control board.	90 Η 84	2	High voltage micro (CCM) bad communication. Communication problems on control board; replace control board.
40 b 87	1	Baffle cooling/position fault.			High voltage micro (CMM) initialization. Initialization fault. Power cycle unit and verify if code remains active; if code still active, replace control board.

Unit Temperatures and Thermistors

Refrigerator Compartment Thermistor

The refrigerator compartment thermistor senses the refrigerator compartment temperature and relays it to the control board.

Thermistor Condition	Action
Open or shorted	EE on UIM Service wrench flashes Fault code logged
High temperature offset reached	Compressor faults to 20 minutes on and 40 minutes off
UIM temperature display	High speed run command sent to refrigerator or freezer evaporator fan
Sabbath mode	Changes one degree per minute; is an average of compartment thermistor readings
Baffle at high offset	15 to 25 second delay before compressor starts
Refrigerator compartment below 2°C	Baffle opens Evaporator fan runs on high

Refrigerator Compartment Thermistor Test

Turn off power to the unit.
Follow the procedure in Component Removal and Installation to expose the refrigerator cabinet thermistor.
Follow the procedure in Component Removal and Installation to expose the control board.
Remove the thermistor harness from the control board.
Place the thermistor into an ice bath of 0°C. Let the thermistor sit for five minutes, stirring occasionally.
Measure the resistance of the thermistor through the board connector.
If thermistor is outside normal values, replace it.

Refrigerator Evaporator Thermistor

The refrigerator evaporator thermistor senses the refrigerator evaporator temperature and transmits it to the control board.

Thermistor Condition	Action
Open or shorted	EE in Service Options - Temps Service wrench icon flashes Fault code logged
3°C to 7°C	Compressor energized Evaporator fan runs at high speed
Evaporator temperature too low after off cycle defrost or during normal cycle	Evaporator fan runs at high speed

Refrigerator Evaporator Thermistor Test

Turn off power to the unit.
Follow the procedure in Component Removal and Installation to expose the refrigerator evaporator thermistor.
Remove the thermistor from the refrigerator evaporator.
Follow the procedure in Component Removal and Installation to expose the control board.
Remove the thermistor harness from the control board.
Place the thermistor into an ice bath of 0°C. Let the thermistor sit for five minutes, stirring occasionally.
Measure the resistance of the thermistor through the board connector.
If thermistor is outside normal values, replace it.

Freezer Cabinet Thermistor

The freezer cabinet thermistor senses the freezer cabinet temperature and transmits it to the control board.

Thermistor Condition	Action
Open or shorted	EE on UIM Service wrench icon flashes Fault code logged
High temperature offset reached	Compressor on 20 minutes and off 20 minutes
UIM temperature displays an average of compartment thermistor	Compressor energized, unless in defrost
Sabbath mode	Changes one degree per minute
Low offset	15 to 25 second delay before compressor starts
During adaptive defrost	Compressor and evaporator fan stopped Freezer temperature display is locked

Testing the Freezer Cabinet Thermistor

Turn off power to the unit.
Follow the procedure in Component Removal and Installation to expose the freezer cabinet thermistor.
Remove the thermistor from the freezer compartment clip.
Follow the procedure in Component Removal and Installation to expose the control board.
Remove the thermistor harness from the control board.
Place the thermistor into an ice bath of 0°C. Let the thermistor sit for five minutes, stirring occasionally.
Measure the resistance of the thermistor through the board connector.
If thermistor is outside normal values, replace it.

Freezer Evaporator Thermistor

The freezer evaporator thermistor senses the freezer evaporator temperature and transmits it to the control board, where it used for the adaptive defrost and to operate the evaporator fan after defrost.

Thermistor Condition	Action
Open or shorted	EE in Service Options - Temps Service wrench icon flashes Fault code logged
Freezer evaporator temperature above 2°C after defrost	Compressor energized after 5 minute defrost dwell
Freezer evaporator temperature approximately 16°C to 21°C	Evaporator fan will not start De-energize the defrost heater

Freezer Evaporator Thermistor Test

Turn off power to the unit.
Follow the procedure in Component Removal and Installation to expose the freezer evaporator thermistor.
Remove the thermistor from the freezer evaporator.
Follow the procedure in Component Removal and Installation to expose the control board.
Remove the thermistor harness from the control board.
Place the thermistor into an ice bath of 0°C. Let the thermistor sit for five minutes, stirring occasionally.
Measure the resistance of the thermistor through the board connector.
If thermistor is outside normal values, replace it.

Component Testing

Condenser Fan Testing

The condenser fan is supplied with 12 VDC at all times. The condenser area temperature determines the speed of the fan. TIP: Test the condenser fan under load.

Verify the control board model configuration is correct.
Disconnect the electrical connector from the fan, and measure the resistance between the power wire and the return wire.
Reconnect the fan.
Check for voltage between the power and return wires.
Check for voltage between the variable speed control and return wires.

Condenser Fan Speed

CONDENSER FAN SPEED
Thermistor Condition	Fan Speed
Approximately 13°C	Low speed
Approximately 24°C	Medium speed
Approximately 35°C	High speed
Open/shorted	High speed

CONDENSER FAN WIRING

Wire Color	Function
Red	Fan power
Yellow/orange	Variable speed control
Blue/orange	Tachometer input
Black/red	Fan return

Evaporator Fan Test

The evaporator has 12 VDC power at all times. Evaporator temperature determines the fan speed. TIP: Test the evaporator fan under load.

Verify the control board model configuration is correct.
Disconnect the electrical connector from the fan, and measure the resistance between the power wire and the return wire.
Reconnect the fan.
Check for voltage between the power and return wires.
Check for voltage between the variable speed control and return wires.

Integrated Evaporator Fan Wiring

The evaporator fan uses a four-wire system to control fan operation. The four wires are fan power, variable speed control out, tachometer input, and fan return. Measuring the DC voltage between these wires should produce the following results.

Test	Measure Result
Fan power to fan return	12 VDC
Variable speed control out to fan return	12 VDC
Tachometer input to fan return	Variable VDC based on fan speed

TIP: Test voltage under load.

EVAPORATOR FAN WIRE COLORS

Color	Refrigerator	Freezer
Red	Power	Power
Yellow	Variable speed control	N/A
Yellow/brown	N/A	Variable speed control
Blue	Tachometer input	N/A
Blue/white	N/A	Tachometer input
Black/red	Fan return	Fan return

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