Gm Mode 22 Scan Tool By Terry !free! Official

The GM Mode 22 Scan Tool by Terry is a legacy, free software utility designed to access manufacturer-specific diagnostic data (Mode 22h PIDs) on older General Motors vehicles. It operates with ELM-based OBD-II interfaces to monitor ECU and TCM parameters, though it lacks support for modern CAN FD protocols and is strictly limited to data retrieval. For a list of free OBD-II software options, including this tool, see Interfuse LLC. OBD-II free software - OBDTester

Your GM vehicle from the pre-OBDII era (1981-1995) uses a 12-pin rectangular ALDL connector (often under the steering column, sometimes marked with a small label). You need a USB-to-ALDL cable that supports the 8192 baud rate. Popular options include: gm mode 22 scan tool by terry

Since the tool is "By Terry," it should leverage his specific diagnostic expertise. The feature would include pre-programmed test routines found in his tutorials: The GM Mode 22 Scan Tool by Terry