The ALDL communications link was originally developed at the General Motors Emissions Control Systems Project Center located at GM's Milford, Michigan Proving ground. It was previously called Assembly Line Communications Link or ALCL. Diagnostics system for General Motors vehicles ALDL 12 pins connector - front viewĪssembly Line Diagnostic Link, Assembly Line Data Link, or ALDL is a proprietary on-board diagnostics system developed by General Motors before the standardization of OBD-2.
