Code B556, Odometer EEPROM Error

Code B556 indicates that the EEPROM,which records elapsed odometer mileage, is not being read by the BCM. Usually along with

Code B556, "ERROR" will be displayed in the odometer display.

• Check for proper EEPROM installation.
• If PROM is properly installed, no bent pins, then replace EEPROM.
  NOTE: New EEPROM will have to be adjusted to the current mileage, proper VIN, and option content by the authorized AC-DELCO service center.
• If a properly installed EEPROM continues to display "ERROR", replace BCM.

Fig 1: Code B556, Odometer EEPROM Error