Gm Mode 22 Scan Tool By Terry |verified| Jun 2026

Cons

GM Mode 22 Scan Tool by Terry: A Deep Dive into Advanced GM Diagnostics

Select the specific PIDs you want to monitor (e.g., fuel trims, knock retardation, timing advance) and hit capture. You can export this raw hex or parsed data directly into CSV format for analysis in software like MegaLogViewer or Excel. Why Enthusiasts Prefer It Over Retail Scanners Generic Handheld Scanner GM Mode 22 Tool by Terry Cost $30 - $100 Free / Low-cost software + basic adapter Data Depth Basic emissions PIDs only Full GM-specific DIDs (ABS, TCM, BCM) Refresh Rate Slow (1-5 Hz) High-speed packed data (20-50+ Hz) Customization None (Hardcoded) Open tables; user can manually add hex addresses Logging Rarely supported or limited Advanced CSV export for tuning integration Safety and Best Practices

The GM Mode 22 Scan Tool (often associated with developer Terry Bleich) is a specialized software program designed to interface with GM’s Assembly Line Data Link (ALDL) systems.

Mode $22 allows a scan tool to request specific data parameters (PIDs) directly from individual electronic control modules (ECUs). This includes data from the: Powertrain Control Module (PCM) Transmission Control Module (TCM) Body Control Module (BCM) Electronic Brake Control Module (EBCM/ABS) gm mode 22 scan tool by terry

: Terry wrote a program that ran on simple PC-based interfaces (like the ELM327 ). It was one of the first times a regular car owner could plug in a cheap laptop and see the same high-level data a dealership mechanic saw.

The GM Mode 22 Scan Tool by Terry might be available as:

Instead of guessing why a car is running rough, you can monitor individual cylinder misfire rates using Mode 22.

Who it’s for

The software was famously designed to run on older DOS or Windows 95/98 laptops, making it perfect for pairing with a budget-friendly, "garage-only" laptop. How to Set Up the Tool

Set the baud rate to match your hardware (typically 115200 bps for CAN-bus vehicles).

The remains a legendary name among General Motors automotive enthusiasts, DIY mechanics, and legacy software collectors. Released during the foundational years of OBD-II diagnostics, this specialized piece of freeware unlocked manufacturer-specific parameter data that standard consumer code readers simply could not reach.

: Like most ELM327-compatible software, it allows users to: Read and clear diagnostic trouble codes (DTCs). Monitor real-time engine data and sensor values. Detect specific system pressures and status indicators. Cons GM Mode 22 Scan Tool by Terry:

Open Terry's software. Go to settings and select the correct COM port assigned to your adapter. Set the baud rate (typically 115200 or 38400).

The tool sends a custom macro command to put the vehicle's data bus into diagnostic mode, silencing non-essential chatter from other modules to clear bandwidth for your data.

: It typically requires an ELM327-based interface (often the USB version) to connect a laptop to the vehicle's 16-pin OBD-II port. Software Ecosystem

Standalone DIY microcontroller builds equipped with a CAN-bus shield. Key Capabilities and Diagnostic Functions Mode $22 allows a scan tool to request