Whenever any CAN device detects an error in a frame, that device transmits a special sequence of bits called an error flag. This error flag is normally detected by the device transmitting the invalid frame, which then retransmits to correct the error. The retransmission starts over from the start of frame, and thus arbitration with other devices can occur again.

CAN devices detect the following errors, which are described in the following topics:

  • Bit error
  • Stuff error
  • CRC error
  • Form error
  • Acknowledgment error