How to Understand Scan Tool

A scan tool (also called a "code reader") is a portable computer that is hooked up to your vehicle's engine to diagnose problems. The scan tool attaches to your vehicle using a data plug and, after the car is turned on, receives one or more codes sent from the vehicle's computer. These codes can be used to determine what is wrong with the vehicle or, at the very least, where the problem is occurring. Other People Are Reading What Automotive Scan Tool Should I Get? How to Close Running Programs to Run ScanDisk Things You'll Need Scan tool Computer Internet access Show More Instructions 1
Turn the vehicle off.
2 Connect the scan tool to your vehicle's data plug, using the appropriate adapter if necessary. The data plug is typically located beneath the steering column on the driver's side of the vehicle.
3 Turn on the vehicle, then turn on the scan tool.
4 Read the code that appears on the display of the scan tool.
5 Open a Web browser on your computer. Navigate to OBD-Codes, AA1Car Trouble Codes or OBDII Codes" (see Resources).
6 Scroll down or click to expand links based on the code(s) displayed in the scan tool. If using the OBDII Codes website, click to select a vehicle manufacturer from the drop-down menu, then type in the code and click "LookUp DTC Information" to display code information.