thanks for responding. The Trans is shifting from 1-2 and 2-3 but it sounds louder when going about 30MPH. It is not stuck in one gear. It just makes me wonder if the overdrive is not working.
Also, I forgot to say-no. The "check engine" light has not come on.
No "check engine" light, no "service engine soon" light.
Alright. Yes, it may well not be going into overdrive.
The only drawback is that since this transmission is electronically controlled the only way to diagnose it properly is with the use of a scan tool and performing some pressure tests as needed.
This is best left to a shop to diagnose. It could be a sensor, or it could be an overhaul.......worse case scenario.