I have been having trouble with my taurus approximately every two weeks, the car is a 2002 with around 45,000 miles. The car will usually start off by sort of shifting into neutral while driving and then it searches to get back into gear. While doing this the transaxle light will flicker and then the check engine light will come on. When I check the codes that come up, there are 21 codes every time this happens. It seems like pretty much all of the codes are for 5 volt reference sensors. I have already changed the coil pack which I thought may have been shocking the system. Once the codes are cleared in the car I can usually drive it around for about two weeks before this problem happens again. I have also taken the car on some longer drives without having this problem occur at all. This problem has happpened both with the engine warmed up and with the engine cold. I am not sure if this could be an ecm problem or a short in the wirirng harness. Does anyone have any idea of what the problem is, or where I should go from here?