Vehicle manufacturers have utilized programmable Electronic Control Units (ECUs) since the late 1990s, beginning with Powertrain ECUs (engine, transmission, transfer case). On today’s vehicles almost all the ECUs are programmable/reprogrammable, utilizing the OEM software to perform service functions. When an ECU is replaced it often requires initial programming to marry it to the rest of the vehicle computer network. Additionally, many repairs today are software updates, rather than parts replacements, and that is completed using a laptop and compatible Vehicle Communication Interface (VCI).