About Code & Clear

Code & Clear is a small independent reference site about car diagnostics. It is organized by warning light and vehicle system, and each page tries to answer one question fully, with the direct answer first.

What you will find here

• Code pages: what a trouble code means, the usual causes and what to test first.
• How-to notes for reading codes, live data, readiness monitors and service resets.
• Tools that decode a code or read your fuel trims for you.
• Narrow gear guides, each about one kind of scan tool.

Where the numbers come from

Code definitions follow the SAE J2012 standard and the published OBD2 requirements. Causes and tests are standard practice for car diagnostics, as found in service information and long-established references. Where sources disagree we give a range instead of a single figure, and we say so. The service information for your vehicle always wins where it differs from a general rule.

How gear is chosen

We do not run a test bench and we do not claim hands-on testing. Gear guides compare products by what their Amazon listings state. How we pick gear explains the method and its limits.

How the site is paid for

Links to Amazon are affiliate links. If you buy through one, the site may earn a commission at no extra cost to you. That is the only income. Nobody pays to be included, and a product is never listed because of its commission. See the affiliate disclosure.

Corrections

If something here is wrong or unclear, write to hello@codeandclear.com. Corrections are made on the page, and its date changes when the content does.