Exceptions to the VIN Decoding Rules
If you have read any of our other articles on VIN decoding you know already that the VIN pattern has certain information that it is required to contain in the US and Canada. However, if you acquire and review a VIN file, like VIN Basic, you will come across exceptions to even these basic rules. Here are a couple of VIN rules exceptions that have lead to questions from our customers in the past.
Multiple Models assigned to a VIN.
Among the most basic information required to be identified by the VIN is the manufacturers "Model" name for the vehicle. While the vast majority of US Passenger and Light Duty Vehicles have VIN patterns that are model specific, there are some rare occurrences of VIN patterns that are used across multiple models. One instance of this, that is probably the most commonly decoded, is the 1994-1996 Chevrolet Impala and Caprice. From 1994-1996 the Impala SS was built as an "option" off the Chevy Caprice from Chevrolet's point of view. As a result, the Impala SS and Caprice share a VIN for those years. This is probably the most popular model combination to share a VIN.
Since the Caprice/Impala SS were built off of a common platform and shared an engine, you can understand how an OEM might have assigned a common VIN pattern. However, Porsche made the same mistake with two vehicles from different ends of their model lineup. In 1992, Porsche introduced the four-cylinder 968. It was their entry level car, replacing the 944. For some reason Porsche assigned the same VIN pattern to it as their top of the line six-cylinder Porsche 911 Turbo. Porsche corrected this by assigning the 968 a new VIN pattern, unique to its model and engine, the next year. But be warned! If you are looking for a used 1992 911 Turbo and find an online classified listing with a price that is too good to be true, verify that it really is a 911 before getting too excited about the deal!
There are literally a handful of US Light Duty and Passenger VIN patterns since 1981 that are not model specific. However, it is enough to occasionally cause confusion and frustration when attempts are made to decode these VINs. While still in the vast majority, if you decode vehicles from both US and Canada you will find significantly more models that share a VIN pattern.
Country Specific Models and Engines
While both the NHTSA and Transport Canada require that the model be identified by the VIN, there is a loophole that can sometimes pop up. Each regulatory body only requires that the VIN be specific for the models sold in their country. Occasionally a manufacturer will assign the same vehicle different model names based upon the country where they will be selling the vehicle. A good example of this is the Buick LaCrosse, as it is sold in the US. From it's introduction in 2004 through the 2009 model year, the LaCrosse was sold as the Allure in Canada, where the term "la crosse" can have a negative connotation. So while the vehicle is almost identical above and below the border, different model names were assigned in each country based on marketing concerns.
Another example of this is the 2010 Jetta SportsWagon, as it is sold in the US. In Canada, it is sold as the Golf Sportswagen. Though sold as two models, many trims of this vehicle share a common VIN pattern. So once again, the VIN is model specific only within each country. In addition, there are similar cases of VW VIN patterns where the model is the same for US and Canada, but the engines assigned to the model/VIN pattern combination may vary depending on which side of the border you are on. So in these cases the VIN is engine specific only if you know what market it was sold into.
These are just a couple of examples, of what is not an entirely uncommon occurrence, when decoding vehicles on both sides of the border. It is something to be aware of when using data to support both US and Canadian markets.
Occasionally, a vehicle manufacturer will assign VINs in error to a short run of vehicles that it produces. This, once again, is rare but does occasionally occur and can result in exceptions to the general VIN Decoding rules. An example of this is the 2009 Kia Borrego. In the 2009 Model Year Kia released the Borrego, an SUV that attempted to target more upscale (for Kia shoppers) buyers. Some early manufacturing runs of the Borrego were assigned an "8" in the "Year Digit" of the VIN signifying that the model Year was 2008 and not 2009. Since their was no 2008 Borrego, this was an easy catch for Kia and they notified the NHTSA of the discrepancy. The fact that their was no MY2008 Borrego also made it easy for data providers to assign the errant VIN's to the the correct model year. So if you are working with a VIN pattern based data file it might be interesting to look and see if it contains a 2008 VIN pattern tied to a 2009 Kia Borrego.
Overall, exceptions to the VIN decoding rules are few and far between. However, they do occur and we hope the examples above help you to anticipate and deal with them sucessfully when they do pop up. Navigating through the nuances and around the exceptions is an important part of sucessfully integrating any automotive dataset with your products. The knowledge, expertise and support that a full-service data company can provide their customers can significantly streamline integration, contributing to your business goals being reached ahead of time and under budget.