I have a 2002 Trailblazer EXT and without warning today the transmission stopped responding after stopping for a traffic light. The fluid level on the dipstick is showing overfilled even when the engine is running. The fluid is clear and does not smell burnt. Does anyone have any suggestions as to what the cause may be? The truck has 170k on it and I don't think that any work has been done to the transmission before. I just got the truck about 2 months ago.