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Gm Mode 22 Scan Tool By Terry Fix Info

Review: GM Mode 22 Scan Tool by Terry

Summary

3. GM Specific Trouble Codes

While it will read standard "Check Engine" codes (Mode 9), it also accesses manufacturer-specific codes that generic tools miss. This includes transmission codes (on vehicles with electronic automatics like the 4L60/4L80E) and body control module codes. gm mode 22 scan tool by terry

Extended Parameter IDs (PIDs): 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." Review: GM Mode 22 Scan Tool by Terry Summary 3

  • Fuel pump relay on/off (prime the system without cranking)
  • Cooling fans (force low/high speed to test relays)
  • EGR solenoid (cycle at idle to check for vacuum leaks)
  • IAC (Idle Air Control) valve (extend/retract to diagnose surging)
  • Injectors (balance test firing one at a time)
  • DIYers and enthusiasts looking for a cost-effective, advanced diagnostic tool
  • Professional mechanics and technicians working on General Motors vehicles
  • Anyone seeking a reliable and feature-rich scan tool for troubleshooting and repairing vehicle issues

The GM Mode 22 scan tool is based on the work of Terry, a well-known DIY enthusiast and mechanic who's been developing and refining his own scan tool solutions for years. The tool is designed to be easy to use, even for those with limited technical expertise, and provides a wealth of information and functionality that's not available with standard OBD-II scan tools. Fuel pump relay on/off (prime the system without

  • Connection Process: The tool's connection process is straightforward, with clear instructions provided for connecting to the vehicle's ECU.
  • Data Display: The tool displays data in a clear and concise manner, making it easy to interpret and analyze.
  • 1986–1995 GM Cars & Trucks (Chevrolet, GMC, Pontiac, Oldsmobile, Buick, Cadillac)
  • Engines: 2.8L, 3.1L, 3.4L, 5.0L, 5.7L (TBI and early MPFI), 4.3L V6, 6.2L/6.5L Diesel (mechanical pump with electronic controls)
  • Control Modules: ‘7165,’ ‘730,’ ‘7747,’ ‘7427’ ECMs, among others.

The core appeal of Terry’s tool is its ability to access PID (Parameter ID) data that most budget scanners simply cannot see. Mode 22 is a specific request mode used by GM controllers to broadcast high-speed, live data. While a standard OBD-II scanner might show you a generic oxygen sensor reading, Terry’s setup allows you to monitor individual cylinder misfire counts, transmission line pressure, and torque converter slip in real-time. This level of granularity is essential for tracking down intermittent issues that don’t always trigger a Check Engine Light.