ISO 9141 Protocol Documents for OBD-II

Here's a URL for searching for '9141' on the ISO website:

If the previous URL is too big use this:

There are four matches to that search: ISO 9141:1989 Road vehicles -- Diagnostic systems -- Requirements for interchange of digital information Pages: 11 Price: CHF 65,00

ISO 9141-2:1994 Road vehicles -- Diagnostic systems -- Part 2: CARB requirements for interchange of digital information Pages: 14 Price: CHF 71,00

ISO 9141-2:1994/Amd 1:1996 Pages: 1 Price: CHF 15,00

ISO 9141-3:1998 Road vehicles -- Diagnostic systems -- Part 3: Verification of the communication between vehicle and OBD II scan tool Pages: 19 Price: CHF 89,00

1 Swiss Franc (CHF) = 0.717001 so that's a total of CHF 240 or about $172.00 US dollars.

The SAE documents can be purchased from

Price: $59.00, or $47.20 for SAE members

Are you getting the gist of this yet?

Copies of Standards, whether in paper or electronic form are *not* free and it is illegal to copy them, period. There may be a fair use exemption but certainly it will be illegal to copy the whole document and redistribute it via email or web pages, etc.

So if you don't want to purchase these standards, your best bet is to visit an engineering library at a university.