Why does my traction control goes on an off when it wants to?

 

Any time a wheel slips or spins on the pavement the traction control will kick in and regulate the power going to the wheel in an effort to eliminate the loss of traction. This is one possibility, and perfectly normal.

It's also possible you may have an intermittent problem that is illuminating the traction light. Having the PCM & EBCM scanned for codes may provide an answer.

 

You probably are in need of an ABS wheel speed sensor change, loose damaged wire going to it or a wheel bearing, buy a TImken, they seem to be highly recommended.
As previously mentioned getting the codes checked will give you an idea of where on the car the problem is ie front left wheel bearing, or rear wheel bearing