Project Gretio

Preview of App

Gretio is a modern scan tool for enthusiasts and professionals alike. It features an advanced dashboard system for viewing various sensor data. It can also perform advanced diagnostics on all of the primary modules you will find in a GM vehicle.

You can download Gretio for free on your mobile device’s app store!

Download on the Apple App StoreDownload on Amazon App Store

See list of known supported vehicles here

Gretio Common Terms & Glossary

Known Issues and Changelog


  • Hundreds to thousands of data features (PIDs) from BCM, ECM, TCM, TCCM, and more
  • Control functions for engine speed, dpf service regens, SCR service tests, and many more.
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  • Auto shut down with vehicle to prevent battery drain.
  • OEM DTC scanner
  • OEM Software Information, part numbers, and CVN History
  • [Android only] Multi Device mode for Multi-Function Displays (MFD) setups.
  • [Android only] Dashboard pages for graphical data.
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  • [Android only] Recording and data graphs

Supported OBD2 Devices

Surreal Development has published a document helping people diagnose emissions issue in select General Motors diesel vehicles

The document is publicly available here.


Note on Android devices: Many OEM heavily modify the core Android OS which is known to cause problems such as companion device manager crashing, failed OBD2 connects, app screen turning off when unwarranted, or app crashes. Most of these issues can be fixed with config settings. See


Gretio has a continuous Open Beta will always be on the Google Play Store: The beta version will have the latest features and fixes, but may have unstable issues or crashes.