Operation CHARM: Car repair manuals for everyone.

ECU Malfunction

The BCM performs an Electrically Erasable Programmable Read-only Memory (EEPROM) checksum as a part of its internal diagnostics as the BCM is operating. When the EEPROM checksum does not equal a predetermined value, DTC B1000 - ECU Malfunction sets. The checksum is the contents of each memory location in EEPROM added together.