Circuit Description
WARNING: This page is about a different car, the 2003 Chevrolet SSR. However, it is still accessible from the selected car via links, so may be relevant.
Each control module runs a program to detect internal memory faults. No external circuits are involved. If a control modules keep alive memory (KAM) has been reset, that control module may set DTC B1004. It is a normal occurrence when battery positive voltage or ground is removed from the module, such as during a battery disconnect.