ABS Warning light on on 1998 GMC Suburban 1500

What should i be looking at to resolve (repair) abs system warning light.

2 answers
abs sensors in the front hubs get dirty and cause this.
This have to be diagnose with a qualified technician. Use the RepairPal Directory to find a shop here; http://repairpal.com/directory?address=91773&car_brand_names=GMC