2005 Galant LS Rear Power Door Locks Not Working

Hello All,

Just bought a used 2005 Galant LS.  It has about 6K miles, and had a
clear Carfax record.

I am having a problem with the car where the power door locks do not
affect either of the rear doors at all.  Neither locking nor unlocking
using the remote or the inside power lock switch make the locks move.
Locking and unlocking the doors manually works fine.

I'm pretty sure this would be covered under the bumper to bumper
warranty.  However, going to the dealership for repair is not very
convenient--if the repair is likely to be cheap (or something I could
do myself), it would be worth the trouble for me.

Any thoughts on what could be causing this?  Anything easy I could
check before taking it in?

Also, can local repair shops be authorized to do warranty work, or does
it HAVE to be through a dealership?


Thanks for any insight,

Phil