For the DIYer: Look for used GM Tech 2 clones or an Autel AP200 (which supports limited Mode 22 on GM). For the pro: Master Mode 22, and you’ll be the person on the forum everyone asks, “How did you find that?”
“That’s the power of Mode 22,” says Terry. “Generic data would show RPM and VSS, but you’d never see the slip. You’d replace the torque converter unnecessarily.” gm mode 22 scan tool by terry
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 For the DIYer: Look for used GM Tech
Is the software perfect? No. You’ll need patience to find a working download and to configure your serial connection. But once it’s running, you will wonder how you ever diagnosed a GM “Check Engine” light without it. You’d replace the torque converter unnecessarily