In Listen Only Mode, a node does not participate in any communication. It will not acknowledge frames, nor send Error frames. ISO-11898 requires a Listen Only Mode for baud rate detection. Listen Only ensures that a unit just connected to the bus does not affect communication among the other units, until the bus communication speed has been determined and set, and normal communication is possible. The CAN error counters are disabled and the Tx Output is disabled. However, IRR13 is set when a message error occurs. Again, see more in the CAN API application note to learn more about the CAN API!