DTC B1000: Control Module Internal Fault (Except IPM): Description
WARNING: This page is about a different car, the 2002 Oldsmobile Aurora. However, it is still accessible from the selected car via links, so may be relevant.
An internal fault detection is handled inside a control module. No external circuits are involved. A control module runs a program to detect an internal fault when power up is commanded with voltage and ground for module present. This program runs even if voltage is out of valid operating range. When a module sets DTC B1000, it will refuse all inputs. A history DTC clears when a control module ignition cycle counter reaches reset threshold, without a repeat of malfunction.