How to Decode VIN Numbers on a Trans Amby Paul DohrmanUpdated November 07, 2017
You can locate the vehicle identification number (VIN) of your Pontiac Firebird Trans Am under the lower right corner of the front windshield, bolted to the dashboard, when looking in from the outside. The VIN has 17 characters and identifies the vehicle uniquely. This serves to track down major crashes it was in as well as deter theft. The information also conveys different features of the car, such as engine type, model year and safety features. Because the Trans Am’s production spans the ‘70s, ‘80s and ‘90s, the meaning of every field has changed over the course of that time, so no single coding applies for all Trans Ams.
Interpret the 10th character as the model year, for model years later than 1980. The interpretation of many other characters varies by model year, so knowing the model year is the first step to decoding much of the rest.
Interpret letters as follows: A->1980 B->1981 … Skip I, O, Q, U and Z. They aren’t used, due to their similarity to other characters. Therefore, Y equals 2000, 1 equals 2001 and 2 equals 2002. Numbers continue up through 2009. So 9 equals 2009, A equals 2010 and B equals 2011.
Interpret the first character as the company of manufacture for models years later than 1980. 1 is for the U.S., 2 is for Canada and 3 is for Mexico.
Interpret the second character as the manufacturer. For the Trans Am, it is G, for GM.
Interpret the third character as the make. For the Trans Am, it’s 2, for Pontiac.
Interpret the fourth, fifth, sixth and seventh characters as determining the body type, model and restraining features. Which character refers to which description has varied through the years. Look up the PDF file vincardXX.pdf at wrath.com/vindecode/, where XX is the model year, in order to be sure of your interpretation.
For model year 1987, for example, characters 4 and 5 are FW for the Trans Am. Character 6 is 1, for two-door coupe. Character 7 is 1 for manual seat belts and 4 for automatic.
Interpret the eighth character as the engine type. It describes the displacement, the cylinder count and the carburetor. Therefore, the table for any one year is too large to reproduce here. See vincardXX.pdf for your model year to determine your engine type.
Ignore the ninth character. GM uses it internally.
Interpret the 11th character as the plant location, for model years after 1980. The list is too lengthy to reproduce here. Refer to vincardXX.pdf.
Interpret the last six characters as the order in which the car came off the assembly line. Pontiac may be able to determine the exact date of manufacture with this number.
Paul Dohrman's academic background is in physics and economics. He has professional experience as an educator, mortgage consultant, and casualty actuary. His interests include development economics, technology-based charities, and angel investing.