I had the abs light come on. Then the brake light came on. When I started driving the speedometer doesn't work under about 25 or so. Also it doesn't shift from first to second until about 2800 rpm or so. It all happened at the same time. Any ideas. fuses all look good.

 

You may have an output sensor on the transmission causing no speedo and for the abs, ck the fuse and see if you have brake lites too. if they are good then the sensor on the back of the rear axle assy,or the abs controller.

 

speed sensor on top of the rear diff.

 

could the speed sensor cause all the problems I'm experiencing. It has to be one thing that knocked everything off. Thanks for the help...

 

You have two sensors. one on the tail housing of the transmission and the other is one the rear diff assy.

 

The brake lights are working.

Is there a way to test the sensors. Or do I just change one and see if it fixes the problem.

 

x2 on this problem. however, my shifts are just fine. i have no spedo under 25mph, and both ABS and brake lights are on. how sure are you guys that the speed sensor on the rear dif is the problem? btw is on a 1999 2500, 8.0l v-10

 

bump

 

I had the exact same problems. I replaced to rear speed sensor on top of the rear differential and it corrected the ABS & BRAKE lights indicators being on, and also made the speedometer work correctly... I also replaced the TPS (throttle position sensor) located on the throttle body, this corrected my eratic shifting...!

 

speed sensor on the rear axle fixed the problem. Thanks.....