Read the archives and still not clear..

First the ABS, Brake and Traction Control lights came on, with the speedo working.

Then the speedo quit completely.

Is this the right rear speed sensor [I hope] or is it the full ABS control module [I hope not].

Also, can the codes for this error be read at AutoZone with their generic reader or do I need a dealer/indy to read this?

Thanks...

Steve