The computer in your Chevrolet is an on-board diagnostic computer that generates and stores error codes. These error codes don't always indicate that there is an actual component failure, though. Error codes are generated when maintenance is required as well as when there is a component failure or malfunction. Once you've fixed the problem or have performed the required maintenance, you need to reset the Chevrolet's computer. To do this, you need a special tool called an OBD scan tool, which has the ability to reset the vehicle's diagnostic computer, clear all error codes, and shut off the warning and check-engine lights.
Locate the OBD port to the left of the fuse panel. You may need to remove the fuse panel cover to access this on some Chevy vehicles. The port will look like an electrical connector port that accepts an elongated pinned electrical connector.
Plug the electrical connector from the OBD tool into the port next to the fuse panel.
Turn the ignition key to the "II" position.
Press "reset" or wait for the check engine and other warning lights to shut off (if your scan tool automatically clears diagnostic codes).
