This is hard do diagnose if the check engine light hasn't come on. To me it sounds like a sensor or a solenoid. There are sensors (Speed sensors) that determine shifting / OD. And shift solenoids that cause the trans to shift. I believe one of them are the problem. However, it becomes a guessing game when there is no light.
Let me know if you have other questions.
Wednesday, February 17th, 2010 AT 8:44 AM