Let me share my story with you that happened last summer. My 2003 MC SS had the traction lite first came on followed by the ABs lite. I took the car to the GM dealer and they did the diagnosis and told me my brake control module was bad and wanted almost $1000 to replace and reprogram it. I took the car home and found this module was attached to the ABs module lower forward side. I disconnected and cleaned the connector and took a hammer and tapped lightly a couple of times on the brake control module and the light has not come on in about 9 months. Try it you have nothing to lose and it could save you money. Just my $.02 worth of the past problem

 

Been a couple of weird weeks. Busy last week, sick this weekend, and busy again this week. Checked tire pressure Friday. All 4 a little high at 33 PSI cold. Car has 30 PSI listed on the tag on the vehicle, I run them at 31. Set all 4 to 31 PSI. The service traction system msg did not come on. Wife drove car Saturday and said it came on. I drove it to and from work yesterday, to work today, and it has not come back on. Still have vibration issues, most notably on accerlation at hwy speeds. Read my Haynes manual, says to check the inner control arms and the axles. Had this issue come up after I replaced the hubs and driver side outer tie rod. Went away (mostly) after replacing the pass. side axle. Now it's back, and as annoying as ever. Still need to get under the car and check wiring harnesses and give the wheels a good jostling. See if the traction system message stays off. Thanks for everybody's help. Will report back again.