DTC B1556 BCM EPROM Write Error for Cadillac Catera 1999

DTC B1556 is an internal body control module (BCM) fault.

The BCM performs a data check on every EEPROM write. The BCM sets this fault if the data does not match after three consecutive attempts.

Stores a DTC B1556 in the BCM memory.

•	The conditions for the fault are no longer present.

•	The use of the scan tool.

•	A history DTC will clear after 50 consecutive ignition cycles if the condition for the fault is no longer present.

Perform the following steps if DTC B1556 is set:

Clear the DTC with a scan tool.
Cycle the ignition switch.
If DTC B1556 is still current, replace the BCM. Refer to Body Control Module Replacement .