Hello,
I am new to the Saab world, having guided my daughter, 18 years old,
when purchasing her first car. It now has about 122,000 miles (196,420
km) on it. She enjoys the car very much. We live in the Great Lakes
region in the U.S.

I've been watching the group for about 4 months and now need some
confirmation of my thinking or guidance.

The car has an automatic transmission. I have no idea which one it is,
if there is more than one option. The engine is a 2.3L fuel injected
When the weather turned cold the "Check Gearbox" indicator came on
after she started the car one morning and the transmission seemed to
be in second gear when shifted to drive. She restarted the car and
things were normal. Now that it is really cold, 0 F  or -18 C, the
indicator comes on but a restart does not change anything. The upshift
is normal to 3rd gear and overdrive.

Of course the manual, which was still in the car when she purchased
it, advises to take it to a dealer. My thoughts are that the
transmission filter and fluid may be in need of a change.

I am mechanically inclined and have done a major engine overhaul on a
tired '87 Mazda 626 which was my son's first car.

Does anyone have any thoughts or experience with this condition?

Thanks in advance for any replies.