Yesterday I had 275/70/18 tires put on my 2006 LX470. They also did an alignment. When I got in the truck the VGRS light was on (not flashing). I went back in and told them, and they said it should go off after driving it. I drove it all the way home, about 20 miles, and it is still on. It doesn't seem to drive any different or otherwise have anything noticeably wrong. What is going on? What do I need to do?