2002 2.0 GL New Beetle won't shift Any suggestion?

Hi everyone,

I have quick question for you guys who know the answer or experienced same problem. I have 2002 Beetle 2.0GL with 5 speed auto transmission. Everything was fine until yesterday. I was driving on I-95 with like 65mph. Suddenly traffic slowed down and I had to slowed down too. When my speed down to the 35mph, engine light turned on and transmission shifted the gear to 2nd by itself. Then I pushed the accelerator and car won't shifted to next gear. I slowed down and parked the car to the emergency lane and turned the engine off. I started the engine again but engine light was still on. After I put the transmission to D and started to drive but it wouldn't shift. RPM goes to 5000 but it doesn't shift to next gear. Basically it stuck on second gear. If I push the accelerator up to the 4000 rpm and take foot off accelerator then it shifts. Right now I'm really not sure what the problem is. Transmission, sensor, valves?