Vehicle Identification Number
Vehicle Identification Numbers (VINs) are used to uniquely identify motor vehicle's. Prior to 1980 there was not an accepted standard for these numbers, so different manufacturers used different formats. Modern day VINs consist of 17 characters that do not include the letters I, O or Q.
Parts of the VIN
Modern Vehicle Identification Number systems are based on two related standards originally issued by the International Organization for Standardization in 1979 and 1980, ISO 3779 and ISO 3780, respectively. Compatible but somewhat different implementations of these ISO standards have been adopted by the European Union and the United States of America.
The VIN is composed of the following sections:
|North American / EU
> 500 vehicles / year
|Manufacturer Identifier||Vehicle Attributes||Check Digit||Model Year||Plant Code||Sequential Number|
|North American / EU
< 500 vehicles / year
|Manufacturer Identifier (third digit is 9 for < 500 vehicles)||Vehicle Attributes||Check Digit||Model Year||Plant Code||Manufacturer Identifier||Sequential Number|
World Manufacturer Identifier
The first three characters uniquely identify the manufacturer of the vehicle using the World Manufacturer Identifier or WMI code. A manufacturer that builds fewer than 500 vehicles per year uses a 9 as the third digit and the 12th, 13th and 14th position of the VIN for a second part of the identification. Some manufacturers use the third character as a code for a vehicle category (e.g., bus or truck), a division within a manufacturer, or both. For example, within 1G (assigned to General Motors in the United States), 1G1 represents Chevrolet passenger cars; 1G2, Pontiac passenger cars; and 1GC, Chevrolet trucks.
The first character of the WMI is the region in which the manufacturer is located. In practice, each is assigned to a country of manufacture. Common auto-manufacturing countries are noted.
|A-H||Africa||AA-AH = South Africa|
|J-R||Asia||J = Japan|
KL-KR = South Korea
L = China
MA-ME = India
MF-MK = Indonesia
ML-MR = Thailand
PA-PE = Philippines
PL-PR = Malaysia
|S-Z||Europe||SA-SM = United Kingdom|
SN-ST, W = Germany
SU-SZ = Poland
TA-TH = Switzerland
TJ-TP = Czech Republic
TR-TV = Hungary
VA-VE = Austria
VF-VR = France
VS-VW = Spain
VX-V2 = Yugoslavia
XL = The Netherlands
XS-XW = USSR
X3-X0 = Russia
YA-YE = Belgium
YF-YK = Finland
YS-YW = Sweden
ZA-ZR = Italy
|1-5||North America||1, 4, 5 = United States|
2 = Canada
3 = Mexico
|6-7||Oceania||6A-6W = Australia|
7A-7E = New Zealand
|8-0||South America||8A-8E = Argentina|
8F-8J = Chile
8X-82 = Venezuela
9A-9E, 93-99 = Brazil
9F-9J = Colombia
Though there are exceptions, the second digit of the VIN is intended be the first letter of the manufacturer's name. In the third position of the VIN, any letter or number may be used to avoid duplication with other assigned WMI's, but the number "9" is reserved for manufacturers of less than 500 vehicles per year. The SAE will then assign a second WMI code that will appear in digits 12-14 of the VIN, with only the last three being the vehicle's sequential serial number.
List of common WMIs
The Society of Automotive Engineers (SAE) in the US assigns WMIs to countries and manufacturers. The following table contains a list of commonly used WMIs assigned to buses.
(Extended WMI is 140)
|46G||Gillig (incomplete vehicle)|
|4RK||Nova Bus (US-built)|
|4UZ||Thomas Built Buses and Freightliner Custom Chassis|
Vehicle Descriptor Section
The 4th through 9th positions in the VIN are the Vehicle Descriptor Section or VDS. This is used, according to local regulations, to identify the vehicle type and may include information on the platform used, the model, and the body style. Each manufacturer has a unique system for using this field.
North American Check Digits
One element that is fairly consistent is the use of position 9 as a check digit, compulsory for vehicles in North America and used fairly consistently even outside this rule.
Vehicle Identifier Section
The 10th through 17th positions are used as the Vehicle Identifier Section or VIS. This is used by the manufacturer to identify the individual vehicle in question. This may include information on options installed or engine and transmission choices, but often is a simple sequential number. In fact, in North America, the last five digits must be numeric.
North American Model Year
One consistent element of the VIS is character number 10, which is required (in North America) to encode the model year of the vehicle.
North American Plant Code
Another consistently-used element (which is compulsory in North America) is the use of the 11th character to encode the factory of manufacture of the vehicle. Although each manufacturer has their own set of plant codes, their location in the VIN is standardized.
Model year encoding
Besides the three letters that are not allowed in the VIN itself (I, O and Q), the letters U and Z and the digit 0 are not used for the year code. Note that the year code can be the calendar year in which a vehicle is built, or a model or type year allocated by the manufacturer. The year 1980 is encoded as "A", and subsequent years increment through the allowed letters, so that "Y" represents the year 2000. 2001 through 2009 are encoded as the digits 1 through 9, and subsequent years are encoded as "A", "B", "C", etc. A number of 2001 MCI coaches were sent out with an incorrect "Z" model year code, but was soon corrected on subsequent builds.
The model year for the VIN starts on September 1, therefore for 1981 the year started September 1, 1980 and ended August 31, 1981. A notable exception concerns the school bus industry, where the large school bus products of Blue Bird, IC Bus and Thomas Built Buses will present with VINs that are a model year ahead, so that the late summer of 2020 would see the first 2022 model buses, for example.
An exception to the above rule is made for electric-powered vehicles, where the year code of the VIN is determined by what is called the "chassis on rubber" date. Therefore the VIN will more accurately date the vehicle.
Check Digit Calculation
Firstly, find the numerical value associated with each letter in the VIN. (I, O and Q are not allowed.) Numerical digits use their own values.
|A: 1||J: 1|
|B: 2||K: 2||S: 2|
|C: 3||L: 3||T: 3|
|D: 4||M: 4||U: 4|
|E: 5||N: 5||V: 5|
|F: 6||W: 6|
|G: 7||P: 7||X: 7|
|H: 8||Y: 8|
|R: 9||Z: 9|
Secondly, look up the weight factor for each position in the VIN except the 9th (the position of the check digit).
|1st: ×8||5th: ×4||10th: ×9||14th: ×5|
|2nd: ×7||6th: ×3||11th: ×8||15th: ×4|
|3rd: ×6||7th: ×2||12th: ×7||16th: ×3|
|4th: ×5||8th: ×10||13th: ×6||17th: ×2|
Thirdly, multiply the numbers and the numerical values of the letters by their assigned weight factor, and sum the resulting products. Divide the sum of the products by 11. The remainder is the check digit. If the remainder is 10, the check digit is the letter X. Valid check digits also run through the numbers zero to 9.
Consider the hypothetical VIN 1M8GDM9A_KP042788, where the underscore will be the check digit.
VIN: 1 M 8 G D M 9 A _ K P 0 4 2 7 8 8 Value: 1 4 8 7 4 4 9 1 0 2 7 0 4 2 7 8 8 Weight: 8 7 6 5 4 3 2 10 0 9 8 7 6 5 4 3 2 Products: 8 28 48 35 16 12 18 10 0 18 56 0 24 10 28 24 16
The sum of all 16 products is 351. Dividing by 11 gives a remainder of 10, so the check digit is "X" and the complete VIN is 1M8GDM9AXKP042788.
Tips for researchers
If a VIN's check digit is known, the next VIN in sequence (assuming all other digits are the same) will have the next check digit in the following sequence:
0 2 4 6 8 X 1 3 5 7 9 (repeat)
If the last digit of the VIN rolls over to 0, then go back two check digits to the left, or the same one that was used when the last digit was 7. If the last two digits roll over from 99 to 00 you will likely need to recalculate the new check digit and start the sequence all over again.
Example: For VIN 1M8PDMBA9HP014287, the next check digits would be 0 and 2 for the VINs ending in 288 and 289, then for 290, the check digit would be the same as 287, or 9. Then for 291 through 299, the VINs would have these check digits: 0, 2, 4, 6, 8, X, 1, 3 and 5. The next check digit for 300 is 8.
A handy Microsoft Excel formula to find the check digit of a VIN in cell A1 is:
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