Our '98 GMC Surburban has been showing signs of its age. I recently replaced a windshield wiper pulse module and have had several major repairs over the past four years. Most recently we have had fits shifting out of park. The system is designed to release when the brake is pressed but something seems to be failing because it takes some time to coax the brake to trip the shift release. Sometimes it is immediate. Sometimes it takes several minutes. I understand there is a module involved but I'd like more specific repair info. Thanks. Doug R.