SAE J1979/ISO 15031-5 set includes the communication between the vehicle’s OBD systems and test equipment implemented across vehicles within the scope of the legislated emissions-related OBD. To achieve this, it is based on the Open Systems Interconnection (OSI) Basic Reference Model in accordance with ISO/IEC 7498-1 and ISO/IEC 10731, which structures communication systems into seven layers. When mapped on this model, the services specified are broken into:
- — Diagnostic services (layer 7), specified in:
- — ISO 15031-5/SAE J1979 (emissions-related OBD),
- — ISO 27145-3 (WWH-OBD),
- — Presentation layer (layer 6), specified in:
- — ISO 15031-2, SAE J1930-DA,
- — ISO 15031-5, SAE J1979-DA,
- — ISO 15031-6, SAE J2012-DA,
- — ISO 27145-2, SAE J2012-DA,
- — Session layer services (layer 5), specified in:
- — ISO 14229-2 supports ISO 15765-4 DoCAN and ISO 14230-4 DoK-Line protocols,
- — ISO 14229-2 is not applicable to the SAE J1850 and ISO 9141-2 protocols,
- — Transport layer services (layer 4), specified in:
- — DoCAN: ISO 15765-2 Transport protocol and network layer services,
- — SAE J1850: ISO 15031-5/SAE J1979 Emissions-related diagnostic services,
- — ISO 9141-2: ISO 15031-5/SAE J1979 Emissions-related diagnostic services,
- — DoK-Line: ISO 14230-4, ISO 15031-5/SAE J1979 Emissions-related diagnostic services,
- — Network layer services (layer 3), specified in:
- — DoCAN: ISO 15765-2 Transport protocol and network layer services,
- — SAE J1850: ISO 15031-5/SAE J1979 Emissions-related diagnostic services,
- — ISO 9141-2: ISO 15031-5/SAE J1979 Emissions-related diagnostic services,
- — DoK-Line: ISO 14230-4, ISO 15031-5/SAE J1979 Emissions-related diagnostic services,
- — Data link layer (layer 2), specified in:
- — DoCAN: ISO 15765-4, ISO 11898-1, -2,
- — SAE J1850,
- — ISO 9141-2,
- — DoK-Line: ISO 14230-2,
- — Physical layer (layer 1), specified in:
- — DoCAN: ISO 15765-4, ISO 11898-1, -2,
- — SAE J1850,
- — ISO 9141-2,
- — DoK-Line: ISO 14230-1,
in accordance with
Table 1.
