Traction Off Light Hard Shifting When It Rains

[lbogie1968]

I've had this 2000 Grand Am since february and whenever we went through slushy snow, (now every rain), the traction off light comes on first and it starts shifting hard, trying to stall at stop lights,and it has a roughh idle.
It had the service engine soon light come on the last time and once we cleared the code (which was about the map sensor) everything worked fine and nothing needed fixed.
Yesterday the traction light came on and it did again, what I said above and by the time the wife got it to my house to have me look at it, the traction off light went out and it was running fine. There was no service engine light this time which means there is no code to pull.
Where I bought it, my mechanic and myself is about to pull our hair out.......WHATS GOING ON HERE?!! PLEASE HELP!!!!!

 

[planenut_2000]

If you have a wheel speed sensor starting to go bad. It will trigger the trac light. It thinks you lost traction to that wheel so it's applying brakes to the opposite side and thats probably what your feeling.
I would still scan it and see if you have any codes, some can be set without triggering the SES light. You had a MAP sensor code before, check the vacuum circuit to it for leaks.
Test drive it with a scan tool attached, watching the wheel speed signal live data, at low speed you should be able to pick one wheel that usually starts to cut out before the others.
Check all the wheel speed sensors for corrosion at the terminals. Check for proper resistance reading thru the sensors.(800-1400Koms). The grand Ams are also noted for having broken wires in the body harness from the wheel speed sensor connector to the ABS module. These are micro fine stranded wires. GM sells the harnesses.