From my 2001 Z28 Owner's Manual:
"When your anti-lock system is adjust brake pressure to help avoiding a braking skid, this light will come on.
If you have the ASR system, this light wiall also come on when the system is limiting wheel spin. You may feel or hear the system working, but this is normal. Slippery road conditions may exist if the low traction light comes on, so adjust your driving accordingly. The light will stay on for a few seconds after the ASR system stops limiting wheel spin.
The low traction light also comes on briefly when you turn the ignition key to RUN. If the light doesn't come on then, have it fixed so it will be there to tell you when the anti-lock brake system or ASR is active."
I don't have ASR, and my "low trac" light has only come on a few times (when ABS is required) or when my rear end hops off the ground real bad.
Oh, and I had my manual handy since I'm trying to figure out what other than ABS or Airbags will set off the "service vehicle" light?