My 1996 S-10 Blazer will not shift sometimes and the ABS light comes on. This problem goes away after I drive it for awhile. The code I get is P0502 (vehicle speed sensor low imput). Would a bad speed sensor cause the shifing problem? Also, where is the speed sensor located? Thanks

Bad bearings mine bad sensors, broken ABS wires,

When I had that problem with the emergency light it was the sensor for emergency brake
The abs and brakes sounds like you are loosing pressure in the system

bad spark plugs and plug wires

When the ABS light comes on the module has detected a fault with the ABS, stored a code and turned on the light. You will need a scan tool to read these codes. Most shops should have the proper tools to do this. The most common are the front ABS sensor which are part of the front hub assembly on the 4X4 model.

They may have the proper scan tool. The ABS codes are read through the OBD II port but if they do not have the ABS software then they will be unable to read the code.

When O/D light blinkg, that means there is a fault code in the computer and there is a problem with the transmission. To determine the problem the codes will need to be retrieved and diagnosed from there.

Hope this helps.

Look at the battery area,go to that area on the front part on the frame area you should see a 12 gauge wire is it corroded?(this is a power ground that goes to ABS and affect ignition if there is a code it would be 1351) If its is corroded move the power ground to a different area

retrieve obd2 codes first, probably a speed sensor problem

You might have a short in your wirring, get it checked before it gets worse

Cheers

Chris

This is your hub assembly that needs to be replaced. My ABS light has been on for a while and I've had this happen before and went away after I replaced it. DEFINITELY try to do it yourself since the part is only $100, to save $400 in labor at a shop.

There are speed sensors for the abs in the front wheel bearing assemblies. Rust builds up and changes the air gap between the speed sensor and the reluctor ring inside of the hub. The rust needs to be cleaned away to restore the proper air gap it fix the problem.

First as ABS goes. The abs light will come on for a number of things. The sensor is ajar. The sensor failed or they aren't wired.
secondly the whole ABS unit might be bad. Getting the ABS mo dual is very expensive and to honest you don't need ABS. all ABS does is replace driving skills you should have all ready. on my blazer i have it disconnected because i felt it was more dangerous then old fashioned breaks. Also when your bake pads are shot this could also trip the sensor. As far as the transmission goes there is a sending unit that reads the information and relays it back to the instrument cluster. He could of very well not wired it correctly or at all.