The VIN System

Posted: Sun Mar 06, 2005 6:35 pm

Saw your item in the library about VINs and thought I would add this. Smile

Here are a few more interesting facts about the VIN system.

Although today it is used for other purposes as well, the vehicle identification number (VIN) system, Dept. of Transportation National Highway Traffic Safety Administration Federal Motor Vehicle Safety Standard (FMVSS) # 571.115, was originally invented to improve the effectiveness of vehicle recall programs. The U.S. developed its system in 1979, to be effective the following, 1980, production season. In other words, the 1981 model year. (Interestingly, Honda jumped the gun a bit and started using the system a year early. Also interesting is the fact that the VIN system parallels some of the coding used by Suzuki since the early 1970s, which at times causes confusion.) The VIN system affects trucks, cars, buses, trailers, motorcycles, and incomplete (shipped "knocked down") vehicles. Boats use a similar system called a hull identification system (HIN), which varies in some particulars, among them the number of characters used (17 are mandated for U.S. model VINs).

While the manufacturer and country of origin have some freedom as to the coding of the VIN's three sections, what is communicated by them is tightly defined by law. As already mentioned, the first three characters uniquely identify the manufacturer, with the very first character signifying country of origin. Vehicles made in places other than Japan have interesting substitutes for the usual "J", such as a "1" or a "9" (U.S., Brazil, respectively). Vehicles made in quantities under 500 are indicated by a "9" as the 3rd character. Characters four through eight identify the vehicle. Included in this section are codes distinguishing a sport bike from a cruiser, and codes for nominal horsepower rating and engine displacement. Characters ten through seventeen record the model year, manufacturing plant, and production sequence number. Bear in mind that the sequence number does not in every case mean that is how many were made. Manufacturers for their own reasons often skip numbers during production. In other words a 000120 serial isn't necessarily the 120th unit manufactured. The model year code in this section is perhaps the most significant piece of the VIN to the average person. Due to another, 1975 FMVSS law, every vehicle is actually stamped with two year designations, one for the year of manufacture and another for the year to be sold. Previous to 1975, manufacturers sold leftover previous year's models as next year's, without ever changing them. Registration also was complicated because the various state's motor vehicle departments regarded the sale year as equal to the model year. In fact this situation continues to plague owners of older vehicles. The 10th character, the model year code, did away with all these problems. The 1981 model year started with a "B" and each subsequent year went through the alphabet, through "Y" for model year 2000. Along the way, the letters "I", "O", "Q", "U" and "Z" were skipped to avoid confusing them with similarly looking characters. In 2001, the system converted to numbers, beginning with a "1". After reaching the "9" in 2009, the system will revert again to letters, beginning with "A" for 2010. In between sections two and three (characters eight and ten) is found the check digit, a special code designed originally as a double-check against errors in transcription. The check digit is derived from a simple formula which applies numeric value to some of the characters and then multiplies and adds them in a certain sequence. When entered into a state computer system on which the (not-so) secret formula has been programmed, an incorrectly copied-down VIN is therefore immediately detected. Of course it has since developed that would-be VIN modifiers are foiled as well, making the check digit today more of a tool for law enforcement than for DMV staff.

More interesting VIN trivia. The lifetime of a VIN is 30 years. That is, the law prohibits any two VINs from being identical within a 30-year period. What this means in a practical sense is that the various governments decided against the likelihood of three things. First, that a vehicle will continue in use for that long. Second, that two vehicles made this far apart chronologically will have identical body style indentifiers. And third, that given the first two coincidences the vehicle will also have the same sequence number. More trivia. Due to a decision on the part of the federal DOT some early post-1980 offroad bikes do not have check digits (just a "0" placeholder). This is odd because they are recalled just as often as road machines. The characters in U.S. VINs are always Sans Serif, a minimum of 4 mm tall, and do not include the letters "I", "O" or "Q", while "U" and "Z" are allowed anywhere but in the model code.

DOT NHSTA FMVSS laws have greatly affected motorcycles. There have been many, some of which have mandated such things as left side shift, how far apart the turn signals must be, the maximum wattages of lights, etc. Very Happy

Posted: Sun Mar 06, 2005 7:19 pm

Neat stuff Mike, Thanks.

Gord Razz