For 1990-2009 cars

### Circuit Description

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

### Conditions for Setting the DTC

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.

### Action Taken When the DTC Sets

Stores a DTC B1556 in the BCM memory.

### Conditions for Clearing the DTC

• | 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.

### Diagnostic Aids

Perform the following steps if DTC B1556 is set:

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