Technology · Data · Protocols
Vehicle Protocols — UDS, WWH-OBD, DoIP, J1939 & ISO 15765-4
A layer-correct embedded guide to ISO 14229-1:2026 UDS, ISO 27145-3 WWH-OBD, ISO 13400-2:2025 DoIP, ISO 15765-4:2021 and the distinct SAE J1939 Classical and CAN FD stacks.
Engineering overview
- Complete 27-service UDS quick reference with positive SIDs, P2/P2*/S3 timing, negative responses, SecurityAccess and Authentication boundaries.
- ISO 27145-3 WWH-OBD core services, multi-DID requirement, DTC access, emissions-group clearing and DoCAN/DoIP connection paths.
- ISO 13400-2 DoIP header, discovery, routing activation, alive check, diagnostic ACK/NACK and UDS-response layer separation.
- Classical J1939 uses J1939-11 plus J1939-21; J1939 CAN FD uses J1939-17 plus J1939-22 Multi-PG and FD.TP.
- ISO 15765-4:2021 defines Classical CAN external-tester candidates using 11/29-bit identifiers at 250/500 kbit/s; 250 kbit/s is a standardized link option, not a universal passenger-car OBD-II default or proof of WWH-OBD.