It's wierd, it's only the Hill Descent Control warning light (the orange one with the !) not CEL, no ABS, no TC light, nothing else. It turned on while pulling into the garage in the rain.

 

So, what have you checked so far, that light should only come on if you are in low range only.
How bad was the rain, any chance you got some water on the electronics, especially under the dash?

 

It's not raining super hard, but enough to need the wipers on high. I for sure wasn't in low range. I pulled into my driveway, waited for the garage door to open, then pulled into the garage. Brakes seem normal. I'm rolling around underneath on a creeper just looking at stuff right now (brake lines, etc). Engine seems to be running fine, no weird noises from pumps or belts. Next I'll check the fuses and relays.

It is possible something got wet I suppose. I do have a new leak in the A pillar that makes the top corner of the headliner get slightly damp, but it's not like it's pouring in. It started a couple weeks ago. I thought it was due to the snow/ice frozen to the roof and maybe clogging one of the gutter drains.

Would a code reader or ABS amigo pick that light up?

 

I'm not really sure what I should be looking for I guess. I'm just looking for anything out the ordinary. I can't find a whole lot of information on the Hill Descent light by itself. It seems to come on by itself only rarely.

I did the hard wired ground bypass on the ABS modulator (abs fix #2 I think people refer to it as) about 6 months ago to get rid of the 3 amigos. I've been driving around in snow using the TC and the ABS just fine for the past month.

 

The light was off this morning on startup. Something to note is that the vehicle did not chime at all when the warning light came on. It's supposed to chime 3 times according to the RAVE manual.

So far everything has checked out as fine mechanically and in the fuse boxes.

 

The rover gods may have shown favor on you this time. Check your cowl area and make sure it is water tight. If not, you can silicon it. Next time, the gods may have more wrath.