DoIP (Diagnostics over IP)

Workshop glossary › Diagnostics & protocols · Updated 2026-04-30

ISO 13400. UDS diagnostic traffic carried over Ethernet rather than CAN. Standard on most premium vehicles since around 2015.

DoIP (Diagnostics over Internet Protocol) carries diagnostic traffic over standard Ethernet instead of CAN. It is defined by ISO 13400, finalised in 2011, and was adopted aggressively by the German OEMs from around 2015 — Mercedes (XENTRY), BMW (ISTA), VAG (ODIS) all use it for ECU flashing.

The pin layout reuses the OBD-II connector: pins 3 and 11 carry Ethernet, with the gateway speaking 100BASE-T1 (single twisted pair) to in-vehicle modules and switching to 100BASE-TX over the diagnostic cable to the tester. Flash times that took 45 minutes over CAN can drop to under 5 minutes over DoIP.

If a workshop's scan tool cannot enumerate any ECUs on a 2018+ Mercedes or BMW, the cable is usually the issue: a CAN-only OBD cable will not establish the DoIP handshake. The manufacturer-specific Ethernet activation cable is required.