Wrench light most likely culprits. Details follow

2007 Ford freestar 3.9  I don't know the trim so I
selected "S". The wrench light came on last night. It
was a cold, wet night. First time it ever happened. The
van sounds good and the only thing noticable aside
from the light is a rough shift after the light comes on.
Restarting the van turns light off. Upon restart no
rough shift until light comes on after approximately 3
minutes at 55mph.
Pcm is dry as a bone with zero corrosion. Same for
fuse box. No lose or damaged wires or connectors.
I really need to know the most likely culprits. I don't
have hundreds to pay for diagnostics and shops
guessing at parts. I am fairly mechanically inclined
and can swap almost any part with a little information.
The internet tells me no codes would show up on the
scanner at AutoZone but you can't trust everything you
see. I need help. It's our only vehicle. Injured at work
awaiting surgery so finances are not good. 4 kids, 2
are special needs, and one on the way.
Can I drive it without destroying it?
Stuck like chuck.
Thank you so much