KWP2000
Workshop glossary › Diagnostics & protocols · UpdatedKeyword Protocol 2000 (ISO 14230). The pre-CAN diagnostic protocol used on European cars from the late 1990s up to roughly 2008.
KWP2000 — Keyword Protocol 2000, ISO 14230 — was the dominant diagnostic protocol on European cars from about 1997 until ISO 15765-4 (CAN diagnostics) took over by 2008. It runs over the K-line, a single bidirectional wire on pin 7 of the OBD-II connector.
The protocol's quirks are why older scan tools struggle with mid-2000s European cars: the bus initialisation uses either a 5-baud slow-init or a fast-init sequence, the tool must keep the session alive with periodic tester present messages, and most service IDs were inherited later by UDS (ISO 14229) — which makes KWP2000 useful background knowledge even when the immediate work is on a newer vehicle.