ABS Question 94 RS

A few weeks ago i was driving on the thruway ( 70mph ) and out of nowhere the abs light comes on. The roads were wet and it was raining i shut the car off and the abs light went out and hasnt come back on. Today i noticed that when i drive on wet roads and i brake the car pulls extreme hard left! Only when the roads are wet. When its dry the car tracks perfect. The abs light hasnt come back on, but i havent had the car up to 70mph yet. Any correlation between the two, could i be having a speed sensor problem and if so any easy way to find out which one?

Mine just came on in the rain as well.It didnt light until the car was rolling at a pretty good pace,wouldnt come on until the car was moving.I think a wheel sensor is either going bad or the heavy rain might have something to do with it,but this is the first time for this.No under car damage has ever occurred so there should be no wire unplugged etc.....
I'm stumped too.
One thing,the ABS solenoid motors work....after starting you can hear them moving.

I think I have the problem located.The left rear wheel sensor has gone "open",with no resistance reading as opposed to the right rear one.The sensor is serviced as the whole hub assy,so I guess I will be changing that one out and see if it solves the problem.Funny thing,there was no trouble code before using the car Wednesday night,I cannot imagine how a wound wire coil that senses a magnetic trigger passing by it suddenly failing.What could go wrong? 35,000 miles? Another part that GM made sure failed under very light usage.

When testing, make sure you turn the wheel with your hand too. It might read open because the wheel is in a certain position. If you look, there are those notches which pass by the sensor. Your reading should change as the wheel moves.