my 2009 impala LTZ doesn't have any switch or indicator lite on dash for Stabilitrak, only for Traction Control. Do others have a switch or lite? I assume I do not have Stabilitrak.

there is no switch for Stabilitrak that I know of, however when you turn the key switch to the on position, you would see all dash lights going on at the same time, you should see yellow colored symbol of a car with curved lines, therefore you should have Stabilitrak. That light would only flash when the Stabilitrak is active.

I got a chance to look up this information on a pdf brochure and Orderbook published May 1, 2009 from GM website. Stabilitrak is standard on LTZs. From an Owner's Manual you can download as a pdf from Chevrolet website under Owner link and then Manuals. As stated in the manual, to turn off Stabilitrak, push down the Traction Control button briefly then TRACTION CONTROL OFF displays and a solid Traction Control light on the gages will indicate that both traction control and Stabilitrak is turned off. Hopefully this helps.