Fleet card providers like WEX use these codes to manage tax exemptions. An "Undefined" code often means the tax-exempt program cannot verify the fuel type, and therefore, standard taxes may apply by default.
In heavy-duty vehicles, the protocol defines Suspect Parameter Numbers (SPNs). SPN 96 is “Fuel Level 1.” SPN 97 is “Fuel Level 2.” But what about SPN 0xFFFF? That is proprietary —reserved for manufacturers. undefined fuel-reserved for proprietary
For each fuel entry include: