The job of the Starter Relay Circuit is to provide a power source to the starter to crank and start the engine. Depending on the specific vehicle and its drivetrain configuration, there can be multiple components involved in this process.If serial data communication is lost between any of the LIN devices on the LIN bus network, the master control module will set a no communication code against the non-communicating LIN device. The Diagnostic Trouble Code (DTC) sets when a supervised periodic message that includes the transmitter device availability has not been received.