Okay, I took her in to the shop, and took a mass of print-offs from here...Trevor's info on the code 25, how to read the codes, info people posted about the AWD and binding etc., as well as the web address for this site. I wonder how many of their customers come in armed...
My son picked her up (I was at work) so I'll call today for more info, but the code wasn't flashing last night. They were researching and checking the code, but I don't know what they did, if anything.(I checked the previous codes before I took it in, and it was the only one that showed up? Does it just show you the last one? Or all codes ever thrown?)
They flushed the tranny, took out the fuse that disabled AWD and drove it around...want me to drive her a few days like that to get the fluid throughout the clutches etc. and see how she does. They felt the AWD might be ok, but won't know until she's driven a bit.
When my son got her, he noticed a noise from the brake (linkage?). So he asked whether they had done anything to it. So a new thing to look at...one step forward, 2 back!
PS Drove my son to work, stopped at brake shop...no problems, just a slightly loose linkage between emergency brake and shifter(?). Went to tranny shop next to ask what teenager didn't when he picked her up...they checked engine torque control and found it working great. Tested wires as per Trevor's post etc. Front end of car fine, and they believe back is good too. Put in stuff (ya, I know, really technical aren't I?)to make it glide and shift better, and so far so good! Mechanic thinks there has been some work on tranny in past, but doesn't think its been replaced. Struts, bearings, suspension (they think fairly new and harded than stock) all look great. So now I'll make an appointment for a cooler and filter install. Thanks to all.