A Controller Area Network, CAN, transceiver configured to be connected to a CAN bus comprising: a transmit input configured to receive transmit data from a CAN controller for transmission on the CAN bus; a transmitter arrangement configured to transmit signalling on the CAN bus based on said transmit data, the transmitter arrangement comprising at least one transmitter configured to operate in a first transmission mode or a second transmission mode, wherein in the first transmission mode the transmitter arrangement is configured to transmit said signalling with a first property and when the transmitter arrangement is in the second transmission mode the transmitter arrangement is configured to transmit said signalling with a second property, different to the first property; a receiver arrangement configured to receive signalling from the CAN bus; a receive output configured to provide received data to the CAN controller based on the received signalling; and a mode detector; wherein the mode detector is coupled to the transmit input to receive the transmit data from the transmit input; wherein the mode detector configured to determine the presence or absence of a first line code encoding of the transmit data; wherein the transmitter arrangement is configured to operate in one of the first or second transmission modes (301, 302) based on a determination of the mode detector that the transmit data is encoded with a first line code and configured to operate in the other of the first or second transmission modes based on a determination of the mode detector that the transmit data is not encoded with the first line code; and wherein the mode detector is configured to provide a mode-switch signal to the transmitter arrangement to select either the first transmission mode or the second transmission mode; wherein the transceiver includes a decoder configured to decode the first line code of the transmit data and provide the decoded transmit data to the transmitter arrangement to provide for said transmission of the signalling on the CAN bus at least when the transmitter arrangement is in said one of the first or second transmission modes; and wherein the first line code comprises a code which gives the transmit data shorter pulse widths than said transmit data that is not encoded with the first line code. a transmit input configured to receive transmit data from a CAN controller for transmission on the CAN bus; a transmitter arrangement configured to transmit signalling on the CAN bus based on said transmit data, the transmitter arrangement comprising at least one transmitter configured to operate in a first transmission mode or a second transmission mode, wherein in the first transmission mode the transmitter arrangement is configured to transmit said signalling with a first property and when the transmitter arrangement is in the second transmission mode the transmitter arrangement is configured to transmit said signalling with a second property, different to the first property; a receiver arrangement configured to receive signalling from the CAN bus; a receive output configured to provide received data to the CAN controller based on the received signalling; and a mode detector; wherein the mode detector is coupled to the transmit input to receive the transmit data from the transmit input; wherein the mode detector configured to determine the presence or absence of a first line code encoding of the transmit data; wherein the transmitter arrangement is configured to operate in one of the first or second transmission modes (301, 302) based on a determination of the mode detector that the transmit data is encoded with a first line code and configured to operate in the other of the first or second transmission modes based on a determination of the mode detector that the transmit data is not encoded with the first line code; and wherein the mode detector is configured to provide a mode-switch signal to the transmitter arrangement to select either the first transmission mode or the second transmission mode; wherein the transceiver includes a decoder configured to decode the first line code of the transmit data and provide the decoded transmit data to the transmitter arrangement to provide for said transmission of the signalling on the CAN bus at least when the transmitter arrangement is in said one of the first or second transmission modes; and wherein the first line code comprises a code which gives the transmit data shorter pulse widths than said transmit data that is not encoded with the first line code.