For the CAN Phy is a half duplex, it can't send ACK signal during CAN message transfer.
So, the K70 FlexCAN module doesn't receive the ACK signal will send CAN message again until this CAN node off line.
It need another CAN node on bus to provide the ACK signal.
If only one CAN node, customer need to use FlexCAN loop-back mode.
Wish it helps.
