Is this illegal to do to your car?

I bought a new car, and rigged up the black box. What I did is make it where I can hit a toggle switch that completely cuts power going to it, so I can just hit the switch real quick and the data will clear. Have to leave the black box on while driving or the abs and airbag lights come on. Is this illegal to do, or is it OK since it is my car, and paid off.