I have a 2004 cavalier. It suddenly started not shifting out of first gear and speedometer quit working. I figured out it was maybe the speed sensor and replaced it then drove fine for about a month. Driving home from work one day and speedometer started moving erratically and quit shifting in yo higher gears. Tried replacing speed sensor again but it did not cure it this time. Wiring to sensor looks good also, any ideas? Thanks.

 

Connector to the sensor, be my guess. Most of the two pin (blue) connectors work on all two pin connectors. Example, I have a crankshaft position sensor connector on my speed sensor as Autozone didn't have that specific, that was 2 years ago.

 

I will check that out. I hope it's an easy fix. Thanks!