A VIN helps identify the right replacement part for your vehicle, but it cannot account for every change. Here’s what sellers need to know.
A vehicle identification number (VIN) is one of the most reliable ways to find the right replacement part. It identifies a specific vehicle, including its engine, transmission, model year, and original sales market. But a VIN lookup can still lead to mistakes if the vehicle has been modified, imported from another market, or built during a model-year refresh.
Here's how to read a VIN and what additional information to provide so the replacement part fits the first time.
The VIN appears in several places on most vehicles:
On your vehicle registration documents.
At the bottom of the windshield on the driver's side, where it can be read from outside the vehicle.
On a label inside the driver's door opening or on the center pillar.
On the vehicle body, either in the engine compartment or beneath a front seat, depending on the make and model.
It's better to take a photo of the VIN than to copy it by hand. If the number on your paperwork doesn't match the number on the vehicle, resolve the discrepancy before ordering parts.
A VIN always contains 17 characters. The letters I, O, and Q aren't used because they can be confused with the numbers 1 and 0. If a parts catalog doesn't recognize your VIN, check whether you entered the letter O instead of the number zero.
Characters 1–3: Manufacturer and country of origin. The codes identify the manufacturer and vehicle origin. For example, WVW identifies Volkswagen passenger cars from Germany, VF is associated with France, J with Japan, K with South Korea, and 1, 4, and 5 with the United States.
Characters 4–9: Vehicle description. This section can identify the body style, engine, and model series. Each automaker uses its own coding system, so this part of the VIN generally requires the manufacturer's catalog to decode.
Characters 10–17: Model year and vehicle identification sequence. For vehicles built for the U.S. and Canadian markets, the 10th character identifies the model year. European automakers don't always follow the same convention, so check the model year of a European vehicle against its documentation.
For example, consider the VIN WVWZZZ1KZ6W000001. The first three characters, WVW, identify a Volkswagen passenger car from Germany. The ZZZ characters are filler characters commonly used in European Volkswagen VINs. The 1K designation identifies the fifth-generation Golf platform, the 10th character, 6, indicates the 2006 model year, and the 11th character, W, identifies the Wolfsburg assembly plant.
Free online VIN decoders can show the make, model, model year, and sometimes the engine. That's often enough to check a vehicle's details before buying it. For replacement parts, however, you'll need the automaker's electronic parts catalog, which lists specific components and their part numbers rather than just general vehicle information.
A VIN-based catalog shows how a vehicle was configured when it left the factory. It doesn't know what happened to the vehicle afterward. These are some of the situations in which a VIN lookup can return the wrong part.
Midyear refresh or supplier change
Automakers sometimes use two versions of the same part within a single model year. Tell the seller the production date shown on the label inside the driver's door opening and send a photo of the old part.
Different factory options
Vehicles with the same trim level may have different brake or suspension components. For Volkswagen, Skoda, and Audi models, option codes may be available on a sticker beneath the cargo-area floor or in the service booklet. Provide those codes to the seller.
A vehicle built for another market
A U.S.-spec vehicle can differ from a European version in its headlights, sensors, and sometimes its brakes. Tell the seller which market the vehicle was originally built for.
A part has already been replaced
A previous owner may have installed an aftermarket part with different dimensions or fitted a component from another version of the vehicle. Provide the markings and measurements from the existing part.
The engine or transmission has been replaced
The VIN describes the original factory-installed powertrain, which may no longer be in the vehicle. If the engine has been replaced, provide the engine code stamped on the block.
This happens often. A catalog may show two or three parts for the same vehicle, with notes such as "through May 2012" or "for vehicles equipped with the Sport package."
Choose based on the fitment notes, not the price. Use the production date from the label inside the driver's door opening, and check the vehicle's options in its documentation or with an authorized dealership's parts department.
If the notes aren't clear, remove the old part when practical and compare its dimensions with the available replacements rather than guessing.
Some drivers order two versions and return the one they don't need. This works only if the store accepts returns on parts that haven't been installed. Check the return policy before paying, especially when ordering special-order parts.
Before placing an order, gather the following information:
VIN: Take a photo of the VIN plate or registration document.
Photo of the old part: If the component has already been removed, photograph its markings and part number.
Measurements and specifications: For sensors, check the number of pins in the electrical connector. For brake rotors, check the diameter and thickness. For shock absorbers, check the length.
Original equipment part number (OE): Ask the seller for the OE number. You can use it to compare aftermarket alternatives from different brands and check compatibility in the manufacturer's catalog.
If you don't want to look up the part yourself, you can ask the seller to handle the search. Many auto parts stores offer VIN-based assistance by phone or through messaging.
Ask the seller to provide the part number and brand along with the price. This lets you verify the selection yourself instead of relying only on the seller's recommendation.
An OE part number identifies a component in the automaker's catalog. Parts sellers use these numbers, and aftermarket manufacturers typically list the OE numbers their products correspond to.
This makes it possible to compare an original part with alternatives from several aftermarket brands using the same reference number.
An aftermarket part is a reasonable choice if it matches the OE number and the required specifications. However, products from different brands can vary in materials, service life, and included hardware. One box may contain mounting hardware, while another may require you to purchase it separately.
Before ordering, ask the seller what comes in the package and how the selected brand differs from similarly priced alternatives.
If a part is advertised as genuine OEM, its packaging should carry the automaker's logo and a part number that matches the manufacturer's catalog. Blurry printing, a sticker covering another part number, or a price significantly below the market average are reasons to ask the seller questions.
First, compare the part number and brand on the packaging with the details on your order. Then place the new part next to the old one and compare their dimensions, mounting points, and connectors.
If anything differs, don't install the part and hope it fits. Stores generally don't accept returns on installed parts, so keep the packaging and receipt until the component has been fitted.
The more information you provide alongside your VIN, the less likely you are to receive a part that doesn't fit.