Tranny problems 02 1.8 Jetta
 

Hi,
I own a 2002 1.8 Turbo Jetta auto-trip with 165k on it, and I think I have a problem:

4 days ago my engine light came on and I decided to ride it out for a few days because I know sometimes they are very sensitive.

However, on the highway back from work I experienced heavy jerks when the gears were shifting (note- I live in toronto and the weather has dramatically dropped in the past 7 days).

After about 10 minutes of experiencing the jerking between gears my traction indicator light also came on.

The jerks continued and the traction indicator light stayed on- 15 minutes later I noticed that I could not get into 5th gear both automatically or using trip.

I have a few specific questions:

1) What (if any) self diagnosing I can do before I send it to the dealer?
2) What (can you speculate on with the information provided) is the problem?

Thanks guys,
Mark