This unit describes the skills and knowledge required to diagnose and repair network electronic control systems. These systems include two-wire high and low speed (CAN-bus) and single wire low speed (LIN-bus) networked circuits essential to control engine powertrain, vehicle dynamic control functions and body control functions. They include vehicle infotainment and climate control systems. The systems used vary based on the work context. The unit involves preparing for the task, sourcing a diagnostic testing strategy, diagnosing the cause of the fault, carrying out the repair, performing post-repair testing, and completing workplace processes and documentation.