in my case, it would go on and off and stay on for 30 minutes. sometimes if i shut off and turn on the car 3x , it will go away. in the end, i took it to the shop and they code read C1274 which meant the G sensor went bad. the G sensor detects if your car's front and rear are slipping, sort of like a gyroscope. if it detect slippage, it activates the antilock brakes. In any case, the piece is only about 2in x 2in and is directly under the emergency break stick. the thing is expensive, costs $222 and can only be bought thru hyundai. 3 months after replacement, it broke again. fortunately its a genuine hyundai part and comes w/ a 1yr warranty/labor , so they replaced it again. we'll see how long this lasts. Both times i had the ABS TCS light go on was when i went down the LIE thru long island. I thought maybe a infrared beam was shorting it but they state its all mechanical. Just my luck it broke a 2nd time.