Theory Of Operation
WARNING: This page is about a different car, the 2014 Fiat 500e. However, it is still accessible from the selected car via links, so may be relevant.
The Electric Vehicle Control Unit (EVCU) performs several basic system self diagnostic checks to ensure proper controller operation.
These checks include read/write memory, checksum, cyclic redundancy check (CRC), main processor and several other internal diagnostics. These internal test are usually implemented on the controllers initial power up.