For Service Technician Use Only
DIAGNOSTICS
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French-Door Bottom Mount Refrigerator
During a Fill Cycle, the GF2 board supplies 115 VAC to P12-4,
opening the Isolation Valve. At the same time, the GF2 board
supplies 115 VAC to P12-6, opening the FC Ice Maker Valve.
After 10 seconds, the GF2 board to ends the Fill Cycle. The GF2
board removes power to the valves, to end the Fill Cycle.
Ice Making
The refrigerator contains an Ice Maker (IM) in the left RC Door.
Some models have a second IM in the Freezer.
Both are Twist Tray Ice Makers, using twisting action of the motor
to break and dump the ice. No heaters are needed for the IM.
All timing, logic, and control is outsourced to the control board
powering the IM.
In-Door Ice Maker
The In-Door IM is controlled by the Dispenser UI and is composed
of the Ice Maker Module.
Ice Maker Module
The Ice Maker module includes the Gear Box, Ice Bin Switch, Ice
Box Temperature Sensor, and Ice Tray Temperature Sensor.
Gear Box
The Gear Box has a 12.7 VDC Motor which drives the Tray Gear,
turning the Ice Tray and operating the Bail Arm through an
associated worm gear. The Bail Arm is used to detect if the Ice
Bucket is full.
The Ice tray position is determined by a wiper arm attached to
the tray gear. As the tray gear turns, the wiper runs over a
resistor ladder. As the wiper moves over the resistance ladder,
the resistance changes. The resistance sensed at any given time
tells the Dispenser UI the position of the Ice Tray.
Ice Bin Switch
The Ice Bin Switch is a spring loaded, normally open switch. The
switch is closed by the Ice Bucket when inserted. The switch must
be closed for the Ice Maker to Harvest ice.
Ice Box Thermistor
The Ice Box Thermistor is mounted on the Ice Maker. It senses Ice
Box temperature as an input into the Refrigeration System.
Ice Tray Temperature Sensor
The Ice Tray Temperature Sensor is mounted to the underside of
the Ice Tray. It reads the temperature of the Ice Tray to ensure
the ice is fully frozen.
Ice Making Process
The standard Ice Making process consists of the following cycles:
•
Homing
•
Filling
•
Freezing
•
Harvest
Homing
When power is initially applied to the Ice Maker, it will move
to the home position. In the Home Position, the Ice Tray is
horizontal and ready to receive water.
Filling
During the Fill Cycle, water is dispensed for 10 seconds. This fills
the Ice Tray with about 3.2 oz. (100 ml) of water. At the beginning
of the fill cycle, the fill tube heater is forced off. The fill tube
heater remains off for 20 minutes. After this time delay, the fill
tube heater will energize and remain energized for 90 minutes, or
until the beginning of the next Fill Cycle, whichever comes first.
Freezing
During Freezing, the IM is waiting for time and temperature
conditions to be met. These conditions vary between the Door
Ice Maker and the Freezer Ice Maker.
For the Door Ice Maker, in the Normal mode, an 80 minute freeze
timer must be satisfied, and the Ice Tray temperature must read
15°F (-9.4°C) before the ice is ready for Harvest.
In Max Ice mode, a 60 minute freeze timer must be satisfied, and
the Ice Tray temperature must read 15°F (-9.4°C) before the ice
is ready for Harvest. The Max Ice feature only affects the In-Door
Ice Maker, and not the Freezer Ice Maker.
During Freezing, the freeze timer will be paused any time an
RC door is opened. When the RC door is closed, additional time
will be added to the timer. The additional time added is equal to
the length of time the door was open. The timer will then begin
counting down again.
Wiper Arm
Resistance
Ladder
Ice Box
Thermistor
