17 printable guides

Free Automotive Diagnostic PDF Guides

Code lists, sensor values and make guides, explained with diagrams and in plain words. All of them are free, in English and Spanish: we only ask for your email to send you the link.

Codes and warning lights

For any make and model.

Shop tests and reference values

Sensors, scanner, battery, A/C, compression and torque.

Make guides

Common faults and manufacturer codes for each make.

Frequently asked questions

How do I get the guide?

Enter your email on the guide page: the download button appears right away and you get an email with the link. The link is personal and allows several downloads for a few days.

What language is the PDF in?

Every guide has an English and a Spanish version. From the English site you get the English PDF; from the Spanish site, the Spanish one.

I did not receive the email

Check your spam and promotions folders. If it is not there, write to us from the contact page with your email address and we will send it again.