I just bought a new car for the wife and I get the bonneville. Now that it is mine I need to fix it to my standards. The problem that I am having is the traction, ABS and one other light comes on usally when driving for a few miles and only in the summer months. The check engine stays off. I live in South Dakota so I have noticed that the lights don't come on in the cooler or freezing months when I really need the ABS and the TC. When the lights come on the ABS doesn't work. I have had it hooked up to a Cornwell scanner and no codes in the computer. It sound like a moisture/temp problem to me. Has anyone had this same problem and what did they do to fix it

Is that scanner capable of reading the ABC and TC systems? Few are. If it is, you should be able to read which wheel speed sensor is causing the problem. It sounds as if you have an intermittent connection. Try cleaning the connection at each wheel speed sensor as a start. Then put a little dielectric grease on the connections.

Well the temps are getting warmer here in south dakota and after a cold winter with the abs and the traction control working perfect --- the lights are now coming back on. It has been about 4 years that it worked perfect during the winter months and doesn't during the warmer months. The only time that it fails during the winter is when I heat the garage to do work on the car -- the abs, traction, and the brake light come on. The funny part is that I back it out of the garage and get a few miles away I can shut off the car and restart it and it is fine -- no lights. This is a heat / humidity issue and I don't know what it could be. I checked the bearing connections and greased them and no luck. I also had it hooked up to another scaner -- the same Cornwell and a Snap-On and both can read Chassis codes and there were no codes. Any other Ideas??

That'* interesting. There should have been at least history codes. If the scanners have the capability, observe the output from each WSS to see if there is a difference. Also, try cleaning up the electrical connection to the electronic brake module.