Hello....I replaced the solenoid pack on the transmission along with fluid and filter change. I am not sure this corrected the problem. It is still doing this but not like it was before. I may be wrong in thinking it was the transmission.....not sure. It does shift more smoothly and it seems the brakes work like new again..[I am not even sure what all this solenoid pack part controled]....Could this have something to do with the engine firing? The car did have the complete tuneup at what was recommended time frame. Is it due for another tuneup at 120K? Would a code show up on the computer on the car also?