Subaru Repair: all wheel drive isnt working, transmission control module, subaru outback

Question
I have a 2001 subaru outback.  I was having problems with getting traction on snow so I spent over $600 on new tires. they are very nice all weather tires.  this did not fix the problem.  After getting stuck on a very small incline a friendly niehbor stopped to push me.  I asked her what wheels were spinning and the only one spinning was the front passenger side.  could this be a problem with my all wheel drive?  maby the transmission contol module. where's the best place to start?

Answer
Hey Christine,

Here is how we would Diagnose the problem at the shop.  We would plug the Subaru select monitor into the vehicle. Rack it on the hoist put it up in the air and put the vehicle in gear.  From there we would look to see if the wheels were moving under power, if not we would look at the data from the select monitor to determine if the solenoid for the transfer clutches is being engaged.  If not we would try and determine why.  I am assuming it is an automatic transmission?  Has the at-temp light been flashing at all?  If so a codes is set in the TCM (transmission control module).  And that is the best place to start.  Most generic code readers as found at a parts store cannot go into the TCM and pull codes so this may have to go somewhere that has a Subaru select monitor or equivalent to be looked at.

Hope that helps