spoonfed

Hi everyone, i just picked up a 91 Lexus LS400 silver trimming with 109k. It was for my dad but i gotta say that in love with it already and almost didn't want to hand him the keys today. The only problem I see so far is the "TRAC" light stays on when I turn on the car. My brother has the same car and he says that the trac light comes on when the traction control unit is doing its thing when for example, i'm spinning my back tires on a turn. What can i start looking into this? Thanks