No it is not likely that the pads caused the light to come on . The light is on because there is a malfunction in the abs system it is more then likely it is a bad wheel speed sensor. Do you know how to pull the codes? Or do you care to? The brakes will still work just no abs as long as the abs light is on.
There are 4 sensors they are about $125 to $165 plus the labor is usually about 1.5 flat rate hours times the shop rate plus what ever diagnostic time they are going to charge. Do you know where there check engine connector is under the hood? It is a little black box about 1 in wide 3 in. long and about 2 in. high it has a snap down lid that says diagnostics. it should be on the passenger side by the right engine mount.
Once you find the diagnostic box open the lid. you need to jump pin TC and pin E1. Turn the key on and watch the ABS light it will begin to flash a series of flashes. They are usually 2 digit codes. 2 flashes then quick pause then 1 flash is an example of a code 21. there is a 3 second delay and the series of codes will repeat themselves. There may be more then one code. No all four sensors are probably not bad at the same time nor do they all need to be replaced just the bad one.
Let me know what codes you get and i will go from there.
I have to call it a night.
I can get back with you tomorrow once you send me the code numbers.
Good luck if you need aynthing in the future let me known.