You're standing in front of a parts shelf at an auto parts store, and the salesman asks, "Are you OEM number do you know? - and at that moment you realize that you forgot to write it down from the box. Or worse: you bought a used spare part without packaging, and now you can’t find an analogue. Is this a familiar situation? OEM number (Original Equipment Manufacturer) is a unique part identifier that guarantees 100% compatibility with your vehicle. Without it, you risk running into a fake, an unsuitable modification, or overpaying for a “universal” option.
In this article we will analyze 5 working waysHow to find out the OEM number - from visual inspection of the part to hidden manufacturer databases. You will learn where exactly to look for markings on the body (spoiler: not always in a visible place), how to decipher the code using the car’s VIN, and why even original catalogs sometimes lie. And also - how to distinguish a real OEM number from a fake one by two signs that sellers are silent about. Are you ready? Let's start with the most obvious - but often overlooked - method.
1. We look for the OEM number on the part itself: where and what the marking looks like
The most reliable way is to remove the old part and inspect it for factory markings. But there are nuances here: manufacturers hide numbers in the most unexpected places. For example, on a generator Bosch the code can be stamped on the back cover under the belt, and on the shock absorbers Kayaba - on the inside of the boot. This is where OEM numbers are most often hidden:
- 🔧 Metal parts (brake discs, hubs, levers): the number is stamped by spot welding or engraving on the non-working surface. Look near the brand logo.
- 🔌 Electronics (sensors, control units): sticker with a barcode on the back or under the protective cover. Sometimes the number is duplicated in a plastic case.
- 🛢️ Rubber products (belts, pipes): the code is imprinted on the inside or under a layer of factory lubricant.
- 🚗 Body parts (headlights, bumpers): markings on the reverse side, often under a layer of primer. A cleaning solvent will be required.
⚠️ Attention: On parts manufactured after 2010, the OEM number may be encrypted in QR code or DataMatrix code (small square mark). Read it using a scanner application (for example, QR & Barcode Scanner for Android/iOS). If the code is not readable, do not rub it with sandpaper! Try taking photos from different angles in good lighting.
If the part is covered with dirt or rust, use WD-40 and a soft brush (such as a toothbrush). Abrasives and metal scrapers can erase markings permanently.
| Part type | Typical marking location | Example OEM number |
|---|---|---|
| Brake pads | On a metal plate (piston side) | 0 986 494 019 (Bosch) |
| Spark plugs | On a ceramic insulator at the base | 24220-22010 (Denso) |
| Stabilizer links | On the boot or under the rubber boot | 34 35 6 783 086 (Lemforder) |
| Engine control unit (ECU) | Sticker on the body or under the cover | 0 261 208 032 (Siemens) |
2. Search for OEM number by car VIN code: free and paid services
If the part has not yet been removed or its markings have been erased, you can find out the OEM number by VIN code car. This method works for 90% of original parts, but requires access to the manufacturer's databases. Here's how to do it:
- Find VIN your car. It is indicated:
- 📄 In STS (line “VIN” or “Identification number”).
- 🚗 On a sign under the hood (usually on the driver's side windshield or on the door pillar).
- 🔑 In the service book (if the car is new).
- Use official catalogs:
- For Volkswagen/Audi/Skoda: service ETKA/ErWin (paid, ~10€ per day).
- For Toyota/Lexus: TechInfo (free for owners).
- For BMW/Mini: RealOEM (free).
- 🌍 VIN-Decoder — free VIN decoding indicating the main details.
- 🛒 Autodoc or Exist — enter the VIN in the search, the system will select the original numbers.
⚠️ Attention: Often found in catalogs outdated numbers (for example, for Ford Focus 2 before restyling in 2008 and after - different codes). Always check the year of manufacture of the car! If the service provides several options, choose the one where yours is indicated in the description. body index (for example, E87 for BMW 1 Series).
3. Online spare parts catalogs: how not to run into fakes
If you prefer to look for an OEM number online, be careful: scammers fake not only parts, but also databases. Here 3 signs of a reliable directory:
- 🔒 HTTPS protocol and a padlock in the address bar (for example, https://www.tecdoc.net).
- 📊 Detailed diagrams indicating the installation locations (not only the code, but also a photograph of the part on the car).
- 💬 Reviews on independent sites (for example, on Drive2 or VAZ Club Forum).
The best free catalogs for finding OEM numbers:
| Service | Features | Supported Brands |
|---|---|---|
| TecDoc | The most complete database for European and Asian cars. There is a mobile application. | VW, BMW, Mercedes, Toyota, Hyundai, etc. |
| ELCATS | Detailed electrical diagrams and electronics numbers. Paid access (~500₽/month). | All brands, including rare ones (for example, Great Wall). |
| CarInfo | Ukrainian service with a base for domestic and Chinese cars. | VAZ, GAZ, UAZ, Chery, Geely. |
⚠️ Attention: In directories like AutoZone or RockAuto often found "universal" numberswhich are not OEM! For example, for a filter Mann code may be specified W 712/94, but the original number for your car is 1 987 432 010. Always check data with official sources.
☑️ Check the OEM number before purchasing
4. Decoding the OEM number: what do the numbers and letters mean?
The OEM number is not a random set of characters. It contains encrypted information about the part, which will help you avoid mistakes when purchasing. Let's look at the structure using a number as an example 8K0 955 115 E (generator for Audi A4 B8):
8K0— model index (Audi A4 8th generation).955— group of parts (in this case, electrical equipment).115— serial number details in the group.E— modification (may indicate market or year specific version).
Different manufacturers have their own rules for generating numbers:
- 🔹 Volkswagen Group (VW, Audi, Skoda): format
X XX XXX XXX X, where the first character is the model series. - 🔹 Toyota/Lexus: number starts with
8or9for original parts (eg90915-20016). - 🔹 BMW/Mini: use prefixes
11 XX XXXfor the engine,33 XX XXXfor transmission. - 🔹 Ford: numbers often contain suffixes like
-AA,-AB, indicating a revision of the part.
⚠️ Attention: If there are letters at the end of the OEM number PR, MR or NR - this is not original, and the part is for the secondary market (aftermarket). For example, 1K0 907 379 PR - this is not the original number VW, and the analogue from TRW.
How to spot a fake OEM number?
Fake numbers often contain:
- Extra spaces or hyphens (for example, 8K0-955-115-E instead of 8K0 955 115 E).
- Non-existent suffixes (for example, /Z instead of standard /A, /B).
- Numbers starting with 000 or 999 - they are not in official catalogs.
5. Mistakes when searching for OEM numbers: what can go wrong
Even experienced car owners sometimes make mistakes when determining the OEM number. Here TOP-5 errors and how to avoid them:
- Confusion with year of manufacture. For example, for Toyota Corolla E150 2010 and 2012 part numbers may differ due to restyling. Always check
body modification(for example,E150orE170). - Ignoring suffixes. Number
1354754and1354754/01- these are different details! The suffix indicates a revision or material (for example,/01- aluminum,/02- steel). - Trust the seller's word. The store may say: “This is the original, just without the box.” Check the number via OEM-Parts or PartInfo.
- The sales market is not taken into account. Details for Europe (code
ECE) and USA (codeDOT) may differ. For example, headlights for BMW E60 have different numbers for left and right hand drive. - Buy by photo. On Avito or OLX They often sell parts with photos where the number is not visible or blurred. Request a clear photo of the markings!
💡 Advice: If you are in doubt about the number, order the part from an authorized dealer using the VIN code (even if you will not buy from them). Compare the number you receive with the one you found yourself. A difference of 1 character - and the part may not fit!
Always check the OEM number with at least 2 independent sources. Even official catalogs sometimes contain errors, especially for rare modifications.
6. Alternative methods: when the OEM number cannot be found
There are situations when the OEM number is erased, the VIN code does not help, and the catalogs are silent. What to do?
- 📏 Measure the part. For bearings, oil seals and rubber products, it is enough to know
inner/outer diameterandwidth. Use calipers and refer to size charts (e.g. for bearings according to SKF). - 📸 Forums and communities. On Drive2 or Club of your brand (for example, Club-Polo for VW Polo) often post photos of parts with numbers. Search by car model and year.
- 🔧 Contact the experts. In specialized services (for example, Automatic transmission or turbines) there are databases of numbers for rare parts. The service is paid (~500–1000₽), but cheaper than buying a “pig in a poke.”
- 🔄 Use cross numbers. If the original number is lost, find an analogue (for example, Febi or SWAG) and use it to restore OEM. Services like AutoCatalogue.
⚠️ Attention: When purchasing using a cross-number, make sure that the analogue is certified for your model! For example, brake pads Ferodo with number FDB1466 suitable for Ford Focus 2, but not for Focus 3 - despite the visual similarity.
FAQ: Frequently asked questions about OEM numbers
Is it possible to drive with non-original spare parts if the OEM number is known?
Yes, but with reservations. If you pick up certified analogue (for example, Brembo instead of original brake discs BMW), this is not only acceptable, but sometimes preferable (better quality for less money). The main thing is that there should be an analogue car manufacturer approval (for example, marking OEM Supplier on the packaging).
❌ It is not recommended to use parts without certification or of dubious origin (for example, “noname” with AliExpress), even if their number is the same as the OEM.
What to do if there are two OEM numbers on a part?
It's normal! For example, the generator may have a number manufacturer (for example, Bosch) and number automaker (for example, VW). To order, use the number automaker - it guarantees compatibility. The manufacturer's number will come in handy if you are looking for analogues.
🔍 Example: on the starter Audi A6 maybe 058 911 023 D (number Audi) and 0 001 110 008 (number Bosch). The dealer needs the first one, and the second one is needed to search for analogues.
How to check the authenticity of the OEM number?
Here are 3 ways:
- Check the number in OEM-Parts database. There are no fake numbers there.
- Compare the font and location of the markings with the photo of the original part (look for Drive2 or in catalogues).
- Request a certificate of conformity from your dealer using this number. Original parts are always certified.
⚠️ Part numbers for BMW, Mercedes and Toyota — check them more carefully!
Is it possible to use the OEM number to find out if a part fits another car model?
Yes, but not always. Some details are unified. For example, 03C 109 084 J (oil filter) suitable for VW Golf 4, Audi A3 8L and Skoda Octavia 1U. Check compatibility via:
❌ Do not rely on the seller’s verbal assurances - even if he says: “100% suitable!”
What is a “super session” and how is it related to OEM numbers?
Super session (super session) is when one OEM number is replaced by another without changing the characteristics of the part. Occurs when a production line is updated. For example, for Ford Focus 2 brake disc number 1 602 858 was replaced by 1 880 427 - but both parts are completely interchangeable.
🔍 How to find out about a super session? In directories (for example, ETKA) there will be a mark next to the number → 1 880 427 or replaced by.