'07 Transmission Problems

[Metaltoon]

Hello everybody! This is my first post to the forum. I just bought my first Yaris 2 weeks ago, an '07 sedan with 130k and an automatic transmission. I put about 50 miles on it after purchasing it private party, and started having an odd issue with the transmission. When I really step on the gas, regardless of speed/gear, the car refuses to shift and hits the rev limiter repeatedly, causing the car to jerk and lurch until I let off the pedal. If I accelerate slowly, it shifts normally.

While I live in a colder climate and it is borderline winter, this is occurring after the cold symbol from the dash is gone, and the car has been driven substantially before hand. I've read every post I can find on here about transmission problems, and haven't been able to gain much insight on the issue. Any help is appreciated. I'm relatively mechanically inclined, but I don't have the resources or time to drop a tranny. I have a local shop I trust for issues I can't handle, but if I don't have to take it there I don't want to

Thanks in advance!!!!