Speed sensor

[txaudifan]

So I replaced my speed sensor and it still does not work. Also put a new axle in on the driver side. My question is; How does the speed sensor pick up information about wheels speed? Is there something in the axle that feeds the sensor, like a magnet or something so the sensor has something to read? I can't think of any other reason on why the sensor is not working. If I can't get this figured out on my own I am going to be forced to pay someone 90 an hour to fix it for me. Thanks guys!!

[Leester]

The CV joint itself has small squares around its perimeter. The sensor rests directly above them. If you remove the speed sensor stare into the hole with a flashlight and you will see these "squares" Im referring to. As the axle spins, the sensor reads these squares to determine the number of revolutions over a period of time (wheel speed). These inputs all feed to dictate traction control. For example, if the input from the front right speed sensor was considerably higher than the front left speed sensor, the traction control program in conjunction with the ABS control module would independently apply brake pressure to the wheel with greater wheel speed until it reached approximately the same speed as the other wheel given steering angle input etc. I would make sure that the speed sensor isnt too covered in gunk and if your subframe is extremely out of place you may need an alignment until the speed sensor code will go away. I once removed my rear subframe from a break due to a stiff swaybar with no reinforcement brackets. When I reinstalled the rear subframe the alignment was so far off that I had speed sensor codes and steering angle input errors. I had an alignment done and cleared the codes.