The first-generation GM Tech 1 scan tool was introduced in the 1980s as a diagnostic tool for GM vehicles. The device was designed to connect to the vehicle's onboard computer system, known as the ALDL (Assembly Line Data Link) or OBD-I (On-Board Diagnostics - I) interface. The Tech 1 provided technicians with a range of diagnostic functions, including reading trouble codes, monitoring sensor data, and performing actuator tests.