ENG 111 indicates engine controller failure. ENG 115-121 cover sensor issues with speed, position, and boost pressure. ENG 131-151 address throttle, oil, and coolant pressure problems. ENG 211-299 cover communication and control module errors
First automatic transmission was 1904 Sturtevant's horseless carriage gearbox. GM Hydramatic became first mass-produced automatic transmission in 1939. Automatic transmissions became standard in large cars since 1974. Global manual transmission market fell from 43% to 37% by 2020
ATF is a hydraulic fluid essential for automatic transmissions. Usually colored red or green to differentiate from motor oil. Contains base oil and additives for specific transmission requirements
Manual transmission requires driver to manually select gears using gear stick and clutch. Early automobiles used sliding-mesh transmissions with up to three gears. Modern constant-mesh transmissions have 5-6 forward gears and one reverse. Manual transmissions are alternative to automatic transmissions
Semi-automatic transmission partially automates clutch operation while requiring manual gear shifting. Types include clutchless manual, auto-manual, auto-clutch manual, and paddle-shift transmissions. Some systems are based on conventional manual transmissions with automatic clutch
AMT combines manual transmission with automatic clutch and gear control. Early versions required manual gear selection, modern ones use electronic control. Modern AMTs can shift gears automatically without driver intervention