94 Cadillac De ville Concourse 4.6 liter?

there are abs sensors attached to each hub and bearing assembly,one of them became unplugged,happens all the time,you can crawl under the rear of the car and see them on the backing plates,just make sure there plugged in,there is a small clip that holds them on.thats it

Were they disc or drum? If disc when changing them you have to push the caliper piston back in so you can fit the thicker pads on, this would make the brake fluid appear low, if you added brake fluid once the piston is pushed it it will make the master cyclinder overfill with fluid, which may be making your abs light come on, another thing is you may have had to open the bleeder valve on the caliper to keep this from happening, in which case it would backwash the fluid into the abs system and make it fault out. If it was a drum setup, they may have not adjusted the self adjusters right, also, sometimes the shoes are bigger and the drum will hardly fit over the new shoes, and once put together it will rub for a day or two insill ti seats correctly, so with the added friction it might be faulting your traction sub-system.

Disconnect the battery for 30 seconds. If the light stays out, you are done. If it comes back on you damaged a sensor while replacing the brakes.

Could be that some debris wound up near the WSS (wheel speed sensor). That kind of thing happens frequently when using an on car brake lathe. But really, any kind of metalic debris would cause that.

when you installed your new brakes you most likely had to bleed the brake system after installing the new parts.....chances are that this told the computer system in your car that you had some serious brake trouble......take it into Cadillac or a GM dealer and ask them to check it out for problems and restet the computer.

Just disconnect the battery for a count of 10 or diconnect the ecm /pcm for about the same time

if you have air in them you need to bleed them there is a splitter right under the driver side floor board you need a certain tool to release the air

you did something wrong