The term “check engine light” seems to be everywhere. The computer in your vehicle is in constant communication with the many sensors and electronic devices throughout your vehicles’ different systems. When the computer detects an inoperative or abnormal sensor reading, it logs an error code and triggers the check engine light on the dash.

Codes can be read with the help of a special scan tool called an Onboard Diagnostics II or OBD-II. When the vehicle is hooked up to the scanner, it reads the code to help narrow down the problem. The codes are a combination of a letter followed by several numbers. These codes help lead the technician in the right direction for the repair.