Undefined Fuel-reserved | For Proprietary

The most common reason for seeing this message is .

Cheap Bluetooth dongles or basic handheld units often lack the licensed library of manufacturer-specific definitions. undefined fuel-reserved for proprietary

In many cases, proprietary fuel codes are triggered by a loose or failing gas cap. It’s a simple, "low-tech" fix that often clears "proprietary" EVAP codes. The most common reason for seeing this message is

If you have a professional-grade tool, it may simply need a firmware update to recognize newer proprietary codes from recent vehicle models. Steps to Resolve the Issue 1. Note the Numeric Code undefined fuel-reserved for proprietary