ABS problems.........

[nycemsmedic]

hey all, have a abs problem on a 97 monty with 96k, 3.1l eng.
I get the following codes:
c1223 LR Speed sensor input signal =0
c1234 " " short to ground or circut open
c1276 LF solinoid circut open or short to ground
c1278 RF solinoid circut open or short to ground
i diagnosed the LR speed sensor and found it inoperational, and i am assuming that the short is secondary to the sensor, tho havent replaced anything yet. where is the solinoids? are they those things on top of the master cylinder? can any1 send me a site that has detalied info on this? such as wiring diagrams, part locations ect. i appriciate all the help. thank you. Dave