What steps should I follow to retrieve diagnostic trouble codes from my vehicle?

First, turn the ignition off and locate the vehicle's 16-pin DLC. Turn the Code Reader off and connect its cable connector to the vehicle's DLC. Then turn the ignition on but do NOT start the engine. After 10-60 seconds, the Code Reader will retrieve and display any diagnostic codes and monitor status stored in the vehicle's computer memory. You can then read and interpret the codes using the LCD display and the green, yellow, and red LEDs.