The invention discloses an ECU
software updating method and device, a vehicle-mounted T-box and a vehicle. The method comprises the steps that after update detection is completed, a positive responsesent by a target ECU is received, and the
positive response is sent to a
cloud server; a
software update pack pushed by the
cloud server is received, and CRC checking is conducted
byte by
byte in thetransmitting and receiving processes; a first CRC and second CRC sent by the
cloud server are obtained, whether the second CRC is identical to the first CRC or not is judged, and if yes, the softwareupdate pack is sent to the target ECU; after the target ECU updates
software to an update area through
byte-by-byte CRC checking operation, data in the update area is read to a buffer area of the vehicle-mounted T-box, and sent to the cloud
server for comparison, if the comparison result indicates the data is identical, a switching instruction is received and sent to target software, and softwareupdate is completed. In the method,
software update is completed through multi-time byte-by-byte comparison of the
software update pack and CRC checking protection, the software updating safety and efficiency are improved, and the use experience of a user is improved.