2mm is very thin, but a good use of all my pad material.
I tried to check through the wheel spokes when I got to work and both looked about 1/4", but it was still not quite light out and hard to see. I'll have to go out at lunch and check.
The light seems to flicker when driving on the highway and goes out with the brakes applied at a stop. Given that the sensor, I think, it just a wire that gets broken by wearing on the rotor, breaking the circuit, that makes sense because the rotor would complete the circuit when stopped.