Gm Mode 22 Scan Tool By Terry !free! Jun 2026

Unlike modern generic scan tools that use a standard J1850 or CAN bus, Terry’s tool sends a specific to the ECM. The ECM responds by dumping a packet of 32–64 bytes of raw RAM data. Terry’s software then decodes that raw hex data into human-readable values.

Disclaimer: The original author "Terry" (full identity and version lineage vary across forums) released this tool as freeware for personal use. Always verify compatibility with your specific ECM ID before use. gm mode 22 scan tool by terry

Most generic code readers cannot send Mode 22 requests. They are locked into universal OBD-II PIDs (Parameter IDs). This is where a dedicated tool, specifically , becomes indispensable. Unlike modern generic scan tools that use a

Mode 22 unlocks manufacturer-specific codes that do not illuminate the Check Engine light but cause drivability issues. Examples include: Disclaimer: The original author "Terry" (full identity and

: Allows users to monitor vehicle performance in real-time by reading raw data directly from the ECU.