Automotive service technicians and mechanics, often called service technicians or service techs, inspect, maintain, and repair cars and light trucks. Service technicians work on traditional mechanical components, such as engines, transmissions, belts, and hoses. However, they must also be familiar with a growing number of electronic systems. Braking, transmission, and steering systems, for example, are controlled primarily by computers and electronic components. Other integrated electronic systems, such as accident-avoidance sensors, are becoming common as well. In addition, a growing number of technicians are required to work on vehicles that run on alternative fuels, such as ethanol and electricity. Service technicians use many different tools, including computerized diagnostic tools and power tools such as pneumatic wrenches, lathes, welding torches, and jacks and hoists. Completing a vocational or other postsecondary training program in automotive service technology is considered the best preparation for entry-level positions. Programs usually last 6 months to a year and provide intensive career preparation through classroom instruction and hands-on practice. Short-term certificate programs in a particular skill are also available.