Automotive Sudoku: Solving for the VIN

What is a VIN?
A VIN, or vehicle identification number, is a unique 17-digit alphanumeric serial number used by the automotive industry to distinctly identify each vehicle, motorcycle, moped, scooter or towed vehicle made both in the US and other countries — serving as both birth certificate and fingerprint. No two vehicles built within 30 years of each other can have the same VIN.
American automobile manufacturers started using VINs in 1954 to identify their own motor vehicles. At that time there was no standard format, so different manufacturers used different formats. In 1981, the National Highway Traffic Safety Administration (NHTSA) established the standardized 17-character VIN.
Not only does it designate for government agencies the exact origin of any vehicle, it has become a most useful investigative tool for consumers who, with just the click of a button, can verify whether a vehicle has been stolen, involved in a major accident, submerged in water, has been classified as a ‘lemon’ or has had the odometer rolled back or reset — before they sign on the dotted line.

The VIN is affixed to every on-road vehicle made in the US after 1981. It can be found stamped into a plate mounted on the dashboard near the windshield, on the driver-side door jamb and on the engine’s firewall. The VIN not only educates consumers on the sometimes dubious history of a vehicle, it is also a deterrent to thieves and an easy way to alert owners of a safety recall.
The Super Secret Decoder
A new vehicle manufacturer is responsible for ‘building’ its own VIN number template using the 17-digit alphanumeric, NHTSA-approved format. This is how it’s done.
Because of its unique position within the mobility industry, SAE International (Society of Automotive Engineers) is contracted by NHTSA to assign a selected portion of the VIN known as the World Manufacturers Identifier (WMI).
Therefore, the first step in the process for a new company is to submit company and vehicle information to SAE and request assignment of the first three characters as well as places 12, 13 and 14 of a new VIN template based on the WMI code.
· Vehicles manufactured in the US may be assigned 1, 4 or 5 in placeholder 1.
· Place 2 is a single initial identifying our company — in this case, ‘A’ for Alkane.
· Place 3 designates how many vehicles we intend to build in a year; building for a niche market (intending to build less than 1000), place 3 = 9.
· Positions 12, 13 and 14 are assigned by SAE based on our intention to sell 999 or less.
· The other positions must be supplied by the manufacturer and largely identify the specifics of the vehicle and city of origin.

· Place 4 is the vehicle model; in this case, we’ll assign a ‘D’ for our new Alkane DOMINATOR™.
· Place 5 describes the vehicle type and can be a letter (weighted with a numerical value) or number; we’ll call this ‘C’ for crew cab.
· Positions 6 & 7 represent the vehicle length in the unit of measure we choose; the DOMINATOR is about 17 feet long.
· Position 8 is the number of axles.
· Position 9 is a special placeholder called the ‘check digit.’ This place serves as a test to validate that the rest of the VIN number is legitimate and remains open until all other fields are assigned. The check-digit validation is compulsory for all road vehicles in North America and substantially reduces fraud by making tampering with a VIN very difficult.
· Position 10 is the model year and each model year has been assigned a representative letter. 2018 has been assigned the letter ‘J.’
· Position 11 is the location of the plant in which the vehicle is manufactured. Let’s say our DOMINATOR is manufactured in Myrtle Beach, SC = M.
· The last three positions (15, 16, 17), because we intend to build less than 1000 vehicles per year, are reserved for sequential production numbers: 001, 002, 003–999.
A Little MOD Math
When all other assigned places and specific descriptors have been filled, it’s time to do the math to determine the all-important check-digit for position 9.
As mentioned previously, each letter place holder is weighted with a numerical value. (The letters I, O and Q are not permitted in VIN numbers.) Also, each of the 17 places is weighted with a numerical value. Modulus 11 (MOD11) is the algorithm used industry-wide to calculate the check-digit by the assignment of weighted values and the application of a formula that checks for errors and redundancy.
The industry refers to the process of replacing for computational purposes each selected letter with a number as ‘transliteration.’ Once the weight for each letter-occupied position is identified through transliteration (using MOD 11), it can be multiplied by the numerical value of the position itself. When computations are completed for each of the 16 assigned positions (the check digit position is represented with a zero), the sum of those calculations is divided by 11. The remaining balance should be the check digit for position 9.
If the instructions for creating a VIN number template cause your eyes to glaze over or send you searching for aspirin, you’re probably not a puzzle lover or a math whiz. But, in spite of yourself, you now know how to dissect your own VIN and what your local motor vehicle or police department is verifying when they run a check on it. Congratulations!
Alkane thanks www.reference.com, www.edmunds.com, www.wikibooks.org, www.sae.org and www.en.wikipedia.org for contributions to this article.
Alkane Truck Company is currently raising capital on the crowdfunding platform StartEngine. Find out more here: https://www.startengine.com/startup/alkane

