I have 96 Maxima SE(auto). My check engine light came on and I got it checked out. The code came as the speed sensor and I had it replaced. The light is back on again. This problem happened last year and when I got a diagnostic check at a Nissan dealership I was told it could be either my Speedo head unit is going or my speed sensor is bad. The head unit is still working well, I changed the speed sensor and I still do not know what the problem is because the car runs fine. If anyone has had a similair problem please email what you did to cure this problem. Thanks, in advance