OBD-I Codes List

What's New

What changed, and when

This page logs every change to the hub with the date it went live: new makes, new codes, new guides and fixes. On this site a code is a number the car blinks out at you, so every entry is checked against a public source before it ships, and each make keeps its own numbering because GM 12 and Ford 12 are different faults.

Newest first.

This hub today

See every code on the hub.

Unverified model claims removed

November 3, 2026

Code pages no longer name vehicle models. Those lists were written during curation and were not backed by the pages each entry cites, so they are gone from code pages, meta descriptions and search snippets. Every code page now carries a Source panel that states the review state, or says plainly that no source is recorded, with the recorded sources nested behind one click. Entries with no recorded source are marked noindex and left out of the sitemap until a source is filed.

The Chrysler side is open

October 10, 2026

The hub now covers Chrysler as well as GM and Ford: 45 OBD-I flash codes for Chrysler, Dodge, Plymouth, Jeep and Eagle, read by cycling the ignition key, plus a guide that walks through it. Each code page gives the meaning, the usual causes and the order to check them.

Cause lists made specific to each code

October 10, 2026

The 137 codes that shared one generic cause list now carry their own, across the GM and Ford sides. Each names the sensor, connector or circuit its own code describes, so two flash codes no longer read the same.

196 more Ford flash codes, and this page

September 29, 2026

The Ford side of the hub grew from 82 two-digit codes to 278, adding the three-digit EEC-IV set. This page now lists every change to the hub with dates, and the footer links the free tools for site owners. See it.

Ford EEC-IV codes opened

September 25, 2026

The hub now covers Ford as well as GM: 82 EEC-IV self-test codes with the key on engine off test, the running test, code 11 as the pass marker, and continuous memory codes.

Code reading guide

September 25, 2026

How to read OBD-I codes without a scanner: the paperclip method, counting flashes, what code 12 means on GM, and clearing codes after the fix.

Breadcrumbs and clearer navigation

September 20, 2026

Every code page shows its path back: Home, then the make, then the code, with the make clickable.

The hub opened with GM

September 19, 2026

68 GM two-digit codes covering Chevrolet, GMC, Buick, Cadillac, Pontiac and Oldsmobile from 1982 to 1995, with the ALDL paperclip procedure on every make page.

Make pages and a browse row

September 19, 2026

Each make got its own landing page with the retrieval steps, and the header carries a make row plus a code lookup from every page.

Still to come

Toyota and Honda each used their own pre-1996 connector and their own code list. No terminal numbers go up for a make until its page is live, because a wrong jumper on the wrong car is worse than no page.

For site owners

OBD-II sites can reuse the generic code list free as CSV or JSON, and the lookup box embeds in your own page: the embed page. All the tools sit together on the tools page.