The USB version can be tested without a vehicle, because when it is connected to the USB port of the computer it receives enough power to operate, indicating this fact with the red led on. One step before engine turns on Step 4, Launch EasyOBD. Of the ELM327xU Interface Scanner is very same functions. ELM327 is used as an interface to connect virtually all OBD-II compliant vehicles to a PC for on-board diagnostics OBD.
