DTC B1556: PZM EEPROM Write Error: Testing
WARNING: This page is about a different car, the 1998 Cadillac Eldorado and 1998 Cadillac DeVille. However, it is still accessible from the selected car via links, so may be relevant.
If DTC B1556 is set, clear DTCs and cycle ignition. If DTC B1556 sets, replace PZM. See REMOVAL & INSTALLATION.