One problem related to brake abs warning light has been reported for the 2002 GMC Envoy. The most recently reported issues are listed below.
When having my 02' Envoy serviced and state inspection by my GMC dealer the service manager called and told me, I would need to r/r my front rotors. The pads were half worn but the rotors smooth surface did not exist. It looked like they were not machined thoroughly. Ser. Mgr thought I lived near the shore, stating salt water would usually causes this. I do not live near the shore and do not go the beach. I drive this vehicle to and from work all highway driving. My vehicle has 41225 mi and has always been serviced by gm. I have owned gm vehicles for 38 yrs and the cars with rotors never looked like this. This looks like a manufacturing imperfection. From reviewing the odi list for this vehicle, others have also documented similar complaints. If I did not bring the vehicle in for the state inspection I would never have know this defect existed. This gave me neither warning in braking, stability nor squealing/ticking from early warning system. I should had asked for old rotors or taken a picture. Front rotors and pads replaced at my expense.