Hi, all,
I just bought a 2003 Jetta without going through mechanical checkup. The car has quite a few missing parts and I thought I can fixed it. However just after three days the car developed more serious problems. It could not pass the second gear. After stepping on gas the RPM reached 6000, it did pass the second gear and the car was able to drive normally. After the car stops and rests for a few hours, the problem comes back.

I stopped by Advanced autoparts and pulled the code. It is P0732
Gear 2 incorrect ratio

Explanation open or short circuit condition

Probable cause
1. Poor electrical connection
2. low transmission fluid level
3. failed transmission solenoid

Since after the car is warmed up, it becomes driveable, could any professional please point out what is the most likely cause and how to repair it?

Thanks.