Turning off abs light.

[sprintster]

I've just bought a Megane Dynamique that had the abs light on.It was just a sensor that had come adrift so I stuck it back in place with JB Weld and when I turned on the ignition the light went out.50 yards up the road it came back on though.If the fault is sorted should the light go out itself or does it need turned off? I've seen YouTube videos of different makes of cars resetting the warning lights by disconnecting the battery and joining the wires together for half an hour.I'm wary of trying this on the Megane though in case it also clears the keycard code.Has anyone else done this?