Double check what exactly that third warning light says. Your Alero also has a ‘service VEHICLE soon’ light, and that is what generally comes on along with the ABS and trac off lights. The most common causes of these lights coming on in these cars are bad wheel speed sensors, which are unfortunately integrated into the hub assemblies, or broken/chafed wiring for the wheel speed sensors. Get the codes read to narrow down where the problem is located so you can start looking for the problem.