Ever have a truck that stumbles but doesn't throw a code? Standard scanners might show a "green light," but Mode 22 can show you that your Long Term Fuel Trims are drifting or that a specific sensor is reporting "noise" just outside the standard threshold.
The GM Mode 22 Scan Tool by Terry might be available as: 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 | Ever have a truck that stumbles but doesn't throw a code
It unlocks access to PIDs like "Oil Pressure" (which many GM trucks don't report over standard OBDII), "Transmission Fluid Temp," and "Desired vs. Actual Idle." Actual Idle
Enter . According to veteran technician Terry, “Mode 22 isn't just another data stream—it's the backdoor into GM’s proprietary brain. If you don't know how to use it, you're diagnosing blind.”