Regulated standardized vehicle diagnostics for emissions-related data and faults.

OBD-II is the second generation of on-board diagnostics for emissions-relevant vehicle diagnostics and is described in SAE J1979. The standard defines diagnostic modes and parameter IDs (PIDs) through which scan tools can query standardized vehicle data and fault codes. For logging, OBD-II is mainly relevant when standardized diagnostic and emissions data are to be captured or evaluated via the OBD connector.