The rising number of ECU units in vehicles today is creating new and more advanced requirements for the CAN bus physical layer. The CAN bus provides a highly robust protocol against communication errors, but the physical layer is the weak point (wires, connectors, etc). For that reason, the fault-tolerant CAN (FT-CAN) was specified. It uses a redundant two-wire communication system which can switch to autonomous single wire communication mode in the case of a bus fault. Each transceiver in a FT-CAN network must have a termination resistor for the CANL and CANH lines.