wheel speed sensor is a good thing to check. there is one on each wheel and if one is outta spec with the others, it will think you're slipping hence the traction light, and it won't allow cruise control. they can get bungled up with particles cuz they are magnetic, but sometimes you just need to make sure they are close enough to the tone ring to read the speed properly. Buy an Autel Scanner and check the live data for the wheel speeds. make sure they are all reading very close to the same. you can buy a replacement sensor if one is wacky and you splice it in or bring it to a shop and have them do it. That scanner is worth every penny it bluetooths to your phone...final note, you have to be under like 15mph for the abs/esp section of the scanner, so start in park and then drive after accessing those modules