BCM Code B556, Odometer EEPROM Error: Notes
Along with Code B556, ERROR will be displayed in odometer display. The EEPROM contains specific vehicle information such as: Vehicle Identification Number (VIN), accumulated vehicle mileage, certain vehicle options and other pertinent information. Information is programmed the specific vehicle in which it is installed and CANNOT be exchanged or used in any other vehicle. Replacement EEPROMs must be obtained through any authorized Delco Electronics Service Center.
NOTE:
New EEPROM will have to be adjusted to current mileage by an authorized Delco Electronics Service Center.