Hyundai Repair: ABS indicator light, hyundai elantra, cv joints

Question
Hyundai Elantra 2002 1.8GLS AT. After replacing both (L&R)parts of the drive shaft (outer part that joined to the wheel), ABS indicator light go on, but the brake function normally during my test drive. What's the problem?

Answer
I see three likely potential issues:

-- The new outer CV joints do not have tone rings (rings with square teeth) on them.  
-- One or both wheel speed sensors were damaged during installation.
-- The wiring to one or both wheel speed sensors was damaged during installation.

If you cannot visually see any issue, it's probably easiest to retrieve the diagnostic trouble code(s) from the ABS module.  The code will correspond to the particular type of issue that's causing the lamp to be on.  Once you know something about why the lamp is on, you'll better know what else to inspect.  A code reader or scan tool capable of interrogating the ABS unit will be required to do this.