Responsible for diagnosing and repairing major systems such as engines, transmissions, air conditioning, air brakes, electrical systems (including multiplex), suspension (including air suspension), exhaust, emission, steering, engine cooling, and charging/starting systems. Success in this role requires expertise with modern diagnostic equipment, including OEM software (Cummins, Ford, General Motors, John Deere), automotive scan tools, oscilloscopes, and multi-meters.