Gm Mode 22 Scan Tool By Terry · Tested & Full

Unlocking Deep Diagnostics: A Guide to the GM Mode 22 Scan Tool by Terry

Terry

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 gm mode 22 scan tool by terry

Cons

"GM Mode 22 Scan Tool by Terry" is legacy freeware commonly bundled with ELM327 OBD-II interfaces for reading enhanced GM-specific diagnostics. Designed for older operating systems, it provides access to specialized vehicle data parameters not available in standard generic OBD-II modes. For modern GM vehicles, users typically transition to factory-level tools like the OEMTools GM MDI or advanced third-party scanners. Interfuse LLC. Obd2 elm327 v1.5 usb can bus scanner | PDF - Slideshare Unlocking Deep Diagnostics: A Guide to the GM

Rating:

4.5/5

Pros

• The "Terry Test": A one-click button that commands the Cooling Fans to High, turns on the A/C Compressor, and commands the IAC (Idle Air Control) to a set RPM. This allows the user to instantly check if the system can handle a high-load thermal stress test.

Why is this a big deal? Because the "Terry" interpretation accounts for the unique scaling and addressing used by each GM ECM. A generic tool might just display "MAF = 127," but Terry’s tool knows that raw value of 127 actually means 12.7 grams/second. That level of specific calibration is why enthusiasts still seek out this tool. The "Terry Test": A one-click button that commands