Code B556, Odometer (Ee) Prom Error

Code B556 indicates that the EE PROM, 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 EE PROM installation.
• If PROM is properly installed, no bent pins, then replace EE PROM.
  NOTE: New EE PROM will have to be adjusted to the current mileage, proper VIN, and option content by the AC-DELCO repair station.
• If a properly installed EE PROM continues to display "ERROR", replace BCM.

When all diagnosis and repairs are completed, clear codes and verify operation.