Hi I'm JOhn I will help you with the problem.
can you fell warm air coming out the front bottom grill ?
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Then pull the fridge out and remove the bottom back panel and clean the coil number 15 if thats dirty it will cause the problem.
The number 2 in the breakdown is the defrost thermostat its located behind the freezer panel clamped to the top of the freezer coil its a common part to fail I would replace the defrost thermostat.