The rising number of sensors, actuators and ECUs over the last few years, has increased the complexity of automotive network. Moreover, multiple network systems are used in today’s cars to meet the different requirements coming from the applications. While Controller Area Network (CAN) is the traditional automotive field-bus, Local Interconnect Network (LIN) provides a low-cost network solution. Network gateway ECU optimizes the cost and efficient management of the complex data exchanges between many ECUs in vehicle. A gateway Electronic Control Unit (ECU) is a central network interconnecting system to link various field buses in a vehicle. As Gateway ECU inevitable even for low cost vehicle in future, a proposal is discussed in this book of a gateway ECU to interconnect CAN and LIN field buses. The proposed gateway ECU has optimal functionality considering the cost competitiveness of low price vehicle segment and this proposal should help automotive community to trigger technology evolution ideas for low price applications.