Mine did that a couple of times during the winter, soon as I backed out of the driveway it went away, hasn't done it since winter, I just chalked it up as some slush/condensation getting into places it shouldn't. who knows? I don't fix things that go away by themselves. If the problem returns and does it again and stays permanently I'd look into it. Like Joe says, a sensor somewhere, wouldn't surprise me if it's not liking the wet weather. No need to panic yet.
Might be inside the vehicle but it happens when it's cold and wet out, now mind ya, mine stopped doing it and it was only a handful of times throughout the winter. If I recall correctly I was also getting a Check E-brake notice or ABS, I do believe it was that, might be off ... two errors on starting the LS, turning it off and restarting always made it go away. Just putting it in reverse and backing out made it go away as well. It was mostly during the extreme cold snaps.
I could care less, it went away, I have one of those self correcting models it would seem. If it acts up again, I'll trace it down but something tells me something underneath is not liking the wet/damp conditions throughout the winters. It's not doing it in the rain, so it's related to cold temps, something freezing up, dampness shorting something related to the wheels.
Generally, the YAW sensor and steering wheel angle sensor should be the only ones that can trip the AdvanceTrac light and not trip the ABS light. An exception might be some sort of CAN bus fault.
When you first start the car, conditions inside are not too far from the conditions outside. Anyway, you need to scan tool that can pull the ABS and other codes to figure it out.
I have check advancetrac on 03 Navigator all the time. I just bought the truck the seller said it was caused by the new coil overs (airbag swap). Does this make sense to anyone here?
I know this is the LS thread but i seen the topic, thanks for the help