An Overview of a Fuel Injection Circuit
In many vehicles, the electrical system is broken down into multiple circuits. The reason behind this is a combination of simplifying the electrical system, simplifying the troubleshooting process, faster and cheaper factory installation process, and being able to reduce cost and weight by eliminating extra wires and cable management products (i.e. harnesses).
Typical fuel injection circuits have an electronic control module (ECM) and various sensors and actuators.