I actually might be able to help (!) as this was happening to me - well, kind of.
My rear tyres were shot, so spinning up in the wet meaning the traction control etc. would flash on, then stay on until I turned the ignition off. I took it in for a service as it was desperate for one.
Turns out my front brake pads where almost non existent and I needed new discs as well. As the traction control comes on, I believe it feathers the rear brakes. As my brake fluid was low, it was all diverted to the rear brakes making the light come on and stay on.
Now I'm not the most technical person in the world - so that explanation might not be the most accurate [people feel free to correct!]
Anyway - check your brake pads and then top up the brake fluid. Worked for me.
Spike