The 17-character vehicle identification number, or VIN on your GM vehicle has all the information you need to look up parts. Once you decode the VIN, use the information to contact any parts dealer. You can decode the VIN on line with automatic decoders for GM vehicles from 1981 to the present year. Or you can do manual decoding for models from 1981 to 2003. Some online decoders send more information than others, and some charge a fee. Pick the one that suits your purpose.
Copy your VIN into the decoder at Decodethis (see References). Click on "Decode." When the next screen appears, scroll down to the tabs and click on each tab for different information.
Copy the year, make, model, style, engine type and engine size on a piece of paper.
Count to the eighth character in your VIN. This number represents your engine size and type. Write that number down on your list in the form "VIN 'X.'" Use the information acquired to order parts from your favorite online or walk-in parts dealer.
For manual decoding, the fourth and fifth characters of your GM VIN identify the make and series (such as Cadillac DeVille or Pontiac Sunfire). The sixth and seventh characters represent the body type and restraint arrangement (such as "four-door sedan" with manual belts and front airbags).The eighth character identifies the year and the ninth results from an formula to prevent fraud. The tenth identifies the year and the eleventh, the manufacturing plant. The eleventh character identifies the manufacturing plant location. See Angelfire in the Reference section for a breakdown of each character.
