Gm Mode 22 Scan Tool By Terry Official

The is a legacy freeware diagnostic software primarily used with ELM327-based adapters to interface with General Motors vehicles. Its core purpose is to leverage GM-specific Mode 22 diagnostics , which allow access to a deeper range of sensor data than standard OBD-II protocols. Key Features

GM Mode 22 Scan Tool by Terry is a legacy, freeware diagnostic application designed to interface with General Motors vehicles through the OBD-II port. It is primarily recognized within automotive enthusiast communities for its ability to access manufacturer-specific data that standard generic scan tools often miss. Overview and Purpose Target Protocol : The tool focuses on gm mode 22 scan tool by terry

| Feature | Mode 01 (Generic) | Mode 22 (GM Enhanced) | | --- | --- | --- | | Refresh Rate | ~1-2 Hz (slow) | 10-20 Hz (fast) | | Parameters | 50-80 basic PIDs | 200+ GM-specific PIDs | | Transmission Data | None or limited | TCC slip, gear ratio, line pressure | | ABS / Airbag Data | No | Yes (via separate module requests) | | Body Control Module | No | Window switches, HVAC actuators | The is a legacy freeware diagnostic software primarily

While professional dealership tools like the GM Tech2 cost thousands of dollars, a developer known simply as released a free, lightweight software utility that could "talk" to GM vehicles using this specialized mode. The Story of a DIY Legend Mode 22 is a specific request mode used

The core appeal of Terry’s tool is its ability to access PID (Parameter ID) data that most budget scanners simply cannot see. Mode 22 is a specific request mode used by GM controllers to broadcast high-speed, live data. While a standard OBD-II scanner might show you a generic oxygen sensor reading, Terry’s setup allows you to monitor individual cylinder misfire counts, transmission line pressure, and torque converter slip in real-time. This level of granularity is essential for tracking down intermittent issues that don’t always trigger a Check Engine Light.