Toyota — OBD-II codes, specs & maintenance

Toyota has built OBD-II compliant vehicles for every major market since the mandate took effect, and its diagnostic behaviour is unusually consistent across model lines. That consistency is why a procedure written for one Toyota usually transfers to another of the same era.

Diagnostic notes

Code prefixes
P0, P1, B1, C1, U0
Protocol
Vehicles from roughly 2008 onward use ISO 15765-4 CAN at 500 kbit/s. Earlier models used ISO 9141-2, and a generic scanner that fails to connect on an older Toyota is usually set to the wrong protocol rather than faulty.
Port location
The connector is almost always under the driver-side dashboard, left of the steering column and above the pedals, often behind a small hinged flap.

Things that catch people out

Models

Last verified 2026-03-14 · Sources: 2018 Camry Repair Manual, engine and emission control section (Toyota Motor Corporation)