SAE J1979

Last reviewed 2026-08-31

ISO equivalent: ISO 15031-5

Defines OBD-II diagnostic services (historically called modes) and the standard Parameter IDs used to request current data, freeze frame, vehicle information, and related emissions diagnostics. Mode 01/02 PIDs and their decoding formulas live here.

Scope. Generic (emissions-related) OBD layer on almost every OBD-II vehicle.

ISO 15031-5 is the ISO counterpart. This catalog stores the publicly documented PID index (number, name, unit, explanation, formula). It is not a substitute for the paid SAE J1979 / J1979-DA document.

Browse the full Mode 01 / 09 PID list →