my trouble free car is now popping up with some gremlins of late. This time, while driving in some fairly hefty snowfall, both ABS and Traction Control System lights come on. Hooked up to good generic OBD-II reader, no codes stored for either system(I think tracs is integral to ABS?). Chilton says that if excessive wheelspin occurs, control module will have a brain fart, and light the lights(I did goose it a bit on one uphill). Lights stayed on during short drive home, not exceeding 25 mph(very wintery here today in Central NY), and stayed on after shutting vehicle off/restart..Could it be as simple as a fuse?..Snow packed in around wheels, would that cause an issue? With no codes stored, don't know where to start w/ the whole diagnostic tree, have tools and time...Will lights clear once diagnosis/ repair performed, or is the a trip to the robber baron known as our local Volvo dealer in order? Thanks to all for any and all help

After you start the car and get around 20mph, the ABS module does a self check and will turn off the lights if no errors are found. I am surprised that your OBDII scanner came up with nothing, but when the roads are clearer, try driving around the block.
I cannot envision enough snow packing the slots in the brake rotor so that the sensors no longer can see the slots. When my daughter sloshed through wet pavement on her 1995, she got the electrics wet enough to set codes and turn the ABS off. After a long wait, days, everything dried and the codes went away.

Klaus
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The 164 has a new home, all I am left with are a 95 854T and a 98 V70R :)

Thank you yet again, KlausC, you were right on the money, drove car for about a mile, and the lights went out on their own, and systems seem normal. Guess spinning the wheels in the snow did cause a temporary brain failure. This is the newest vehicle I've ever owned, so still amazed/perplexed sometimes by all the electronic wizardry found in the modern automobile. Should you ever find yourself in Central NY, the beers are on me..

Guzzle, guzzle, slurp, slurp. Ahhhhh!

Virtual beers :)

Klaus
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The 164 has a new home, all I am left with are a 95 854T and a 98 V70R :)