Food in the frig has been freezing even when the freezer is set to 3 and the frig is set to2 (mod. pss25mgmb) the unit is only about 6 yrs old

it will be cheaper to first get a technician out to diagnose the problem and then decide from there
as it is freezing food , the compressor is working and that is the biggest repair cost that would point to a new unit
at 3 years old , check for the warranty period as it could still be covered

change the thermostat. Is normally a cheap repair.

Sounds like you may need to clean and vacuum out the condenser coils under the unit.

I have this same refrigerator, also purchased in 2006. Same exact problem. Fridge freezes, starting actually in the water line, you will notice water on door does not work, then top two shelves start to freeze. Lasts for a few days, then prob does not happen again for 6 months almost to the day. I've had this problem for almost 3 years!!! My service tech said to buy another, glitch in this system he can't figure out. Replaced damper x2, control board, and thermostat x2. Not sure what else to do. I hate the thought of more food lost to spoilage!

Good day,
This problem appears in spades this time of year, every year.
The problem becomes more severe when the temperatures in the house cools down and is made even worse if the usage of the machine becomes lighter.

It occurs when the machine is off, not on.
There is an open vent, near the bottom, between the freezer compartment and the fresh food compartment. This opening or vent is necessary when the machine is running, so that the air pumped into the top of the fresh food section, can return to the freezer compartment. This is by design.
Now,
When the machine is off, the zero degree air from the freezer compartment. can drift into the fresh food compartmnet and drop the temps near the bottom to below freezing.
Off time increases substantialy at this time of year.
Some have even recommended turning the controls colder to offset the problem, but I've no proof it works well, or even a little.
SXS and top freezer models experience it more than bottom freezer models.

Not fixed but I do not want to spend MORE money to find out what's wrong with this AMANA piece of ****. Apparently, from research on the net, the compressor or motor is not strong enough in this unit to actually do the job...but if anyone has any suggestions, I'm happy to hear them...

you need to replace the start components on the compressor, theres a relay that mounts on to the compressor that takes out the start winding after it starts the compressor up. You can also try whats called a three in one to try to start up the unit. Good Luck.

Check the air dampers at the bottom of the fresh food section.They may have been moved to a open position. If so close them up some.
Otherwise the cold control thermostat may need to be replaced.

Adjust the temperature control for the freezer to a normal setting. Fast freeze is only for when new products are put in that need to be frozen. This locks the system into a continuous run mode and could be responsible for the freezing condition in the refrigerator section. Check the temperatures with a thermometer as the sensor for the freezer temperature could be bad causing the light to come on.

Go to the link below and the choose line 22 and click it. That link page helps identify most common problems you may have with your refrigerator, Thanks Sea Breeze.
 http://www.applianceaid.com/refrigerator.html