2000 Buick Century Transmissions

I went off the exit from highway and came into a stop sign, as I brake, my car started to vibrate. I started noticing that my car jerks when it was shifting to higher gear, also the service engine soon light came on. I turn the engine off and parked it and left it for about 2 hours. I tried driving it again and it was fine, it was running smooth no jerks when shifting gears. But the service engine soon light is still on, could you help me figure what the real problem is? Thank you