Is it OBD-II, and which communication protocol
Quick answer
Every passenger car and light truck sold new in the United States from the 1996 model year is required to support OBD-II through a standard 16 pin connector. Controller Area Network signalling, ISO 15765, became mandatory for the 2008 model year, so vehicles between 1996 and 2007 may use one of several older protocols instead. The OBD2 year range by market: United States 1996, Europe 2001 for petrol and 2004 for diesel (EOBD), Canada 1998, Australia 2006. The five OBD2 communication protocols are SAE J1850 PWM, SAE J1850 VPW, ISO 9141-2, ISO 14230 (KWP2000) and ISO 15765 (CAN).
Between the start of OBD-II and the 2008 CAN mandate, five signalling protocols were permitted. Any scan tool sold as OBD-II compliant supports all of them, so this affects older cheap adapters and home-made cables far more than it affects real scan tools.
Compliance guarantees access to emissions related powertrain data through a standard connector. It guarantees nothing about ABS, airbag or other modules, which is why full system coverage is a separate question from OBD-II compatibility.
This is a regulatory timeline, not a statement about any particular vehicle. Some manufacturers adopted OBD-II or CAN earlier than required, and a few 1994 and 1995 vehicles are partially compliant.
| Make or group | 1996 to 2007 (typical) | 2008 and newer |
|---|---|---|
| General Motors | SAE J1850 VPW | CAN (ISO 15765) |
| Ford | SAE J1850 PWM | CAN (ISO 15765) |
| Chrysler, Dodge, Jeep | ISO 9141-2 or SAE J1850 VPW, by model | CAN (ISO 15765) |
| European makes | ISO 9141-2 or KWP2000 (ISO 14230) | CAN (ISO 15765) |
| Asian makes | ISO 9141-2 or KWP2000 (ISO 14230) | CAN (ISO 15765) |
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Live data and full system access are what most of the answers above depend on. A basic reader gives you the code number and nothing to check it against.
Coverage varies by tool and by model year, so check a specific tool against a specific vehicle before buying.
Tools for the era you entered
- Autel
Autel Original OBD1 to OBD2 GM Adapter Cable
Under $25 Check priceBudget band; Amazon shows the current price - Autel
Autel 7 Pin OBD1 to 16 Pin OBD2 Diagnostic Adapter Cable for Ford
Under $25 Check priceBudget band; Amazon shows the current price - Autel
Autel Euro5 6 Pin OBD1 to 16 Pin OBD2 Adapter Cable Connector
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Common questions
What are the OBD2 communication protocols?
Five signalling protocols are allowed under OBD-II: SAE J1850 PWM (Ford, 1996 to 2007), SAE J1850 VPW (General Motors and some Chrysler), ISO 9141-2 (many Asian and European makes and Chrysler), ISO 14230 KWP2000 (Asian and European makes, roughly 2000 onward) and ISO 15765 CAN, which every US vehicle has used since the 2008 model year. The connector pins populated tell you which one a car uses: pins 6 and 14 for CAN, 2 and 10 for J1850 PWM, 2 alone for VPW, 7 and 15 for ISO 9141 and KWP2000.
When was OBD2 mandatory, and is it ODB2 or OBD2?
OBD2 (often typed ODB2) was mandatory on every passenger car and light truck sold new in the United States from the 1996 model year, in Europe as EOBD from 2001 for petrol and 2004 for diesel, in Canada from 1998 and in Australia from 2006. The correct spelling is OBD, for on-board diagnostics; ODB is a common transposition and means the same thing when you search for it.
What year did OBD-II become required?
In the United States, OBD-II was required on all passenger cars and light trucks from the 1996 model year. Europe followed with EOBD, required on petrol vehicles from 2001 and on diesel vehicles from 2004. Some manufacturers implemented the standard a year or two early, so a 1995 vehicle is occasionally partially compliant.
Which OBD2 protocol does my car use?
For a 2008 or newer US vehicle, CAN (ISO 15765), because CAN became mandatory that model year. For 1996 to 2007 it depends on the maker: GM mostly used SAE J1850 VPW, Ford SAE J1850 PWM, and most European and Asian makes ISO 9141-2 or KWP2000, with Chrysler split by model. The pins populated in the 16 pin connector give it away, and any scanner sold as OBD-II compliant speaks all five, so this mainly matters for older cheap adapters.
Will one scanner work on every OBD-II car?
For generic emissions related powertrain codes, yes, because that is exactly what the standard guarantees. Beyond that the answer changes: access to ABS, airbag, transmission and body modules depends on the tool having specific coverage for that manufacturer, and coverage varies between tools and between model years even within one brand.
Why does my old adapter not work on a newer car?
Older and cheaper adapters sometimes support only a subset of the five permitted signalling protocols. Controller Area Network became mandatory for the 2008 model year, and an adapter that predates that or that cut corners may have no CAN support at all. Any current tool sold as OBD-II compliant supports all five.
Where is the OBD-II connector located?
The standard requires it within reach of the driver seat, and in practice it is almost always under the dashboard on the driver side. Exact placement still varies: it can sit behind a trim panel, above the pedals, inside the centre console or beneath an ashtray. Check the owner handbook for the specific vehicle rather than assuming a location.
Can I read a pre-1996 car with a cheap adapter?
Not with a generic OBD-II tool. Pre-OBD-II vehicles used manufacturer-specific systems with different connectors and different code lists, so reading one requires a make-specific reader or the correct adapter cable plus a tool that understands that manufacturer’s protocol. Some vehicles of that era can also flash their codes out on the dashboard lamp without any tool.
