What's in a VIN?

June 1, 2008
Decoding Vehicle Identification Numbers puts the brakes on auto theft, cloning and chop shop operations

     There are only a handful of times vehicle owners must know an auto's Vehicle Identification Number (VIN): when buying or selling a car, applying for insurance or registering a vehicle with the state Department of Motor Vehicles (DMV). Other than that, few people pay much mind to the series of numbers and letters on a vehicle's dash.

     But because there are those among us who are experts at manipulating a vehicle's VIN to conceal its true identity, it pays to know what's in a VIN. Law enforcement officials in particular should be familiar with the data a VIN contains as well as the methods crooks use to alter or obliterate this information.

What's in a VIN?

     A VIN is a series of numbers and letters that represent coded forms of vehicle information. The coded data found in this series adds detailed vehicle information to what is already found in the DMV's license plate database.

     VINs for vehicles manufactured between 1958-1970 may have 11 numbers and letters or less, while all automobiles manufactured in North America since 1971 contain a series of 17 numbers and letters.

     Sgt. William Smylie, whose career in vehicle theft investigations with the Miami (Florida) Police Department spanned nearly three decades, describes the elements of a 17-digit VIN as follows:

  • World Manufacturer Identifier (WMI). This information is found in the VIN's first three characters. The first character identifies the nation of origin. For instance, Canada is a 2; while the United States can be 1, 4 or 5; and Japan is a J. The second digit indicates the corporate manufacturer, such as Ford, General Motors, Toyota and so on. These numbers or letters may vary according to the place of manufacture. So, for instance, a General Motors vehicle, built in Canada would have a VIN that starts with 2G, while a VIN for an import from Japan, such as a Toyota vehicle, might begin with JT or 1T, depending on whether it was produced in Japan or the United States. The third character indicates the type and model of the vehicle, such as Chevrolet or Dodge.
  • Digits four through nine. The VIN's next five digits give information on various components of the vehicle such as body style, engine type, transmission and drivetrain category. The ninth character is a number known as the "check" digit. This number is part of a mathematical formula, which when applied tells investigators whether the VIN is authentic. Each character in the 17-digit VIN is assigned a corresponding value and weight. The first eight characters' values are added together, as are the last eight. The total sums are then divided by a specified number, which gives a remainder that should equal the check digit's value.
  • Vehicle Indicator section. This is the last eight characters (of a 17-digit VIN). The character in position 10 indicates the vehicle's model year. The codes alternate between numbers and letters according to the year in which the vehicle was produced. All VIN's use numerals from 1-9, and all the letters of the alphabet except I, O and Q. Therefore a vehicle built in 1971 would be a "1" while a vehicle manufactured in 1979 would have a "9" in the 10th position. A vehicle produced in 1980 would have an "A" in the 10th position and so on. (Each year after 1980 is assigned a letter of the alphabet with the exception of I, O and Q until it reaches Z, then the 10th position reverts back to numbers.)
Where's the VIN?

     Before 1967, a VIN could be placed almost anywhere on the vehicle. After 1968, North American manufacturers were required to place the code in an area visible from outside the vehicle. This data string is usually found on the left-hand side of the dash next to the vehicle's lower edge. However, in some older vehicles, the VIN may be on the right side, and in some European models, such as BMW, it may even be situated on the steering column.

     Federal regulations in Canada and the United States require the VIN to be affixed in such a way that removal or alteration is difficult. Each manufacturer uses a unique type of plate or embossing process to achieve this, and it is possible to determine the manufacturer just by the VIN plate style or sticker. For example, General Motors uses a plate, which includes a barcode and is attached with six-point rivets. Ford, on the other hand, utilizes an embossed plate with no barcode, while Honda employs round rivets and Toyota uses five-point rosettes, Smylie reports.

Double protection

     Vehicle manufacturers locate paper labels, known as safety certificates, on the inside edge of the driver's door. Smylie reports these labels contain similar information to that found in the VIN, but also may house a barcode, assembly date information, the gross vehicle weight, axle ratios, transmission information and key codes. In newer vehicles, Smylie notes this certificate may also describe anti-theft devices.

     Data found on the door label can be compared to — and should match — that found in the dash-mounted VIN. However, there may be several reasons why the VIN and safety label do not agree. The vehicle could: Be stolen or registered under a false VIN, have been badly damaged and the dash or door replaced, or have been written off and repaired by a "backyard mechanic" for resale.

     Under these circumstances it is wise to investigate further. VINs are stamped or affixed to most major vehicle parts, and comparisons should be made to several of these areas if a discrepancy is found.

Secret hiding places

     Other VIN locations, sometimes referred to as anti-theft labels, can be found in numerous places. For instance, VINs are stamped or affixed to the front fender and bumper, the hood, the left and right door, rear quarter panels, the trunk and the rear bumper. Sometimes VINs are imprinted on rear passenger doors as well. The codes are also stamped on the engine, transmission and drive train to discourage reassembly of wrecked or stolen vehicles. And some, but not all, vehicles will also have the serial number positioned in confidential locations, such as under the carpets; on the interior of the vehicle's "A" post, the support that runs from the top of the front door along the windshield, or "B" post, the support that runs midway through the vehicle; and on firewalls.

     The VINs in these locations may be whole or partial. In addition, vehicles with higher-end, anti-theft devices may not be required to stamp this data in all of the above locations.

     Data found in these areas are designed to prevent "chop shops" from taking wrecked or stolen vehicles and reconstructing them for sale.

     Damaged vehicles are often repaired with factory-issued parts, which bear what is called an R-dot, basically a sticker affixed to all factory parts that is nearly impossible to remove without obvious damage. 3M Company produces a sticker used by several major manufacturers that displays stripes on both the removed piece and the remaining portion when tampered with. Other stickers in use leave a residue that is visible under ultra-violet light. Manufacturers closely monitor the distribution of replacement parts through the use of such tracking methods, says Smylie.

     Airbags also display a serial number that in most new cars can be matched to the VIN. However, unless the vehicle has had the airbags deployed, examining them must be left to an expert. Airbags carry enough force to kill an adult and should not be accessed by anyone other than an expert in this field, Smylie advises.

A whole new VIN

     There are two ways to alter a VIN. The simple way is to obliterate the digits, which may be removed, chiseled, covered up or otherwise rendered unreadable. This technique is used to slow police down by making it harder for law enforcement officials to identify the vehicle or its owner. Eventually, using data found in other VIN locations, officials will learn whether the vehicle has been stolen or is wanted in a crime-related offense. It is just that without the dash-mounted VIN, it takes longer to process the vehicle and access hidden VIN locations.

     The most difficult changes to catch are the forgeries. Police officers typically are not trained to detect minor VIN changes. They run the VIN through whatever database they use, and if the vehicle description matches the auto in front of them, they do not question the VIN's authenticity.

     Changing the identity of a vehicle is complicated — it involves altering all VIN locations on that auto. These modifications are usually done in vehicle "cloning" operations where a salvage vehicle is recovered and a VIN from an operational automobile is substituted for the original. This is commonly done with high-end vehicles, such as Lexus or Cadillac SUVs.

     When these crimes are discovered it is often due to the way the VINs have been changed. The criminal element may use the wrong rosette or incorrect plate type or forget to change all the numbers found on the vehicle.

Forensically speaking

     Let's say detectives confiscate a vehicle and they suspect the VIN has been tampered with. Generally when examining a vehicle for forensic proposes, the vehicle is divided into three sections: the engine compartment, the passenger area and the trunk. The forensic inquisition proceeds in that order unless murder or suicide is involved in the investigation. And there are other simple steps to take in the investigation.

     (1) Photograph the dash-mounted VIN and label accordingly.

     (2) Photograph all concealed VIN stamps or labels that can be reached without damaging them.

     (3) Coat accessible areas, without damaging the VIN stamps, with fingerprint powder and transfer the images to a fingerprint card and label accordingly. (In cases where officials are trying to view unreadable VINs on the frame, use brake cleaning fluid to clean the area only after photographs and impressions of the original state have been taken.)

     (4) Fingerprint all areas where tampering is suspected. Use a scale indicator and have some way of identifying the photographer. As usual, document the location from which the pictures and other information are located.

     The average motorist may submit a vehicle VIN to the DMV or the insurance company and forget about it. Law enforcement officials lack that luxury. To detect stolen vehicles, uncover chop shops or identify cloning operations, officers need to know what's in a VIN and where it can be found.

     Editor's Note: For online charts decoding VINs, see www.autocheck.com/?siteID=0 or www.greatoldcars.com/decoding.htm.

     Kathy Steck-Flynn teaches seminars in recognition of forensic evidence and forensic entomology for various groups, and is staff writer for "Crime Watch Canada," for which she writes the Forensic Science section. Steck-Flynn can be reached at [email protected].

Decoding a sample VIN

Sample VIN: 1G1FP22PXS2100001

What these numbers mean:
1 = Country it was produced (United States)
G= Manufacturer (General Motors)
1= Make (Chevrolet)
F = Carline Code (F-Body)
P = Carline Series (Camaro)
2 = Body Type (2-door, coupe, hatchback)
2 = Restraint Systems (Manual belts [drive+pass inflatable])
P = Engine Code (5.7L V8)
X = Check Digit (most likely X)
S = Model Year (1995)
2 = Assembly Plant (St. Therese)
100001 = Production Sequence

     — Courtesy of www.thebiglot.com

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