09a Transmission Issues

My girlfriends car w/ the 09a trans is not going into 4th or 5th when warm or cold. It'll go into third when warm but slip when the rpms are below 3500. When the trans is really cold it won't go into any forward gears, only reverse.

Does anyone know what this is symptoms of? I will rebuild this trans if I have to but I'm gonna try my best to avoid that.

Have you tried a drain and refill with Idemitsu type J ATF fluid?

I can give that a try if I can find that in my area, I'll try just changing it with what I can find that is completely compatible.

I ordered a case off ebay, it was far cheaper than anything local I could find.