How to decode OEM VW part number and Audi part numbers

Introduction

This article explains the Audi or Volkswagen part numbering system.  This does not include how to decode VIN numbers or equipment on your car because that's a different thing.  

Part numbers can be found through ETKA (ekta is something else), the electronic parts number catalog for Volkswagen Auto Group (VAG).  Only dealers have the official legal copy of ETKA.  You can purchase access to an online ETKA from its publishers but there are free older ETKA online catalogs out there as well to find the part numbers you want.  In addition to VW, VAG includes Audi, Skoda, SEAT, and Lamborghini because they share many components.  Understanding VAG part numbers will quickly let you cross reference parts across models.

For example, the part number "058 133 843" is for an air filter that fits 04-05 VW Passat 2.0 TDI.  However, it also fits 98-05 Passat 1.8T, 96-02 Audi A4 1.8T, 96-01 Audi A4 V6, and a variety of other V6 and V8 Passat and Audi Allroad, S4, and S6.  This gives some insight into the myth of high performance air filters.  If the 138 hp TDI engine uses the same air filter as the V6 twin turbo Audi S4 and V8 Audi S6, I'll bet it can flow enough air for the TDI engine to accommodate any performance modifications.  See 1000q: basic performance upgrades - chip tuning for the basic steps in increasing power of a TDI.

Many dealers don't give out part numbers because if you're asking for them they know you might try to find the part cheaper online.  Some parts departments will give frequent customer discounts or be cheaper on large bulky items so there are reasons to shop at the dealer vs. online other than convenience.  However, I've also found markup of 2-300% on a few small parts at the local dealer vs. an online dealer.  When ordering parts online that may have not been original to your car (like when retrofitting OEM parts or modifying parts) from a dealer, be careful when giving them your VIN number because it could be rejected as not equipped on your car.  If this happens, you may get the part equipped on your car instead of the retrofit part you ordered.  This is done to prevent ordering mistakes.  To prevent this, make sure the order has a note that you are modifying something.  This shouldn't apply to OEM parts ordered through an independent, non dealership seller.

Except for hardware like bolts, all modern VW and Audi parts have a part number printed or stamped somewhere on them.  They're not always visible unless you flip the part over and if they're printed, they can be rubbed off.  Here's an example of the part number for the OEM coolant block heater on an Audi A3 TDI.  Because it's on the handle the number could be rubbed off through use.

Generic OEM suppliers
You may also see other part numbers on the part that don't look like VW numbers.  These are from the suppliers who build the component.  For example, VW doesn't build radios, filters, or timing belts.  These are purchased from companies like Blaupunkt, Bosch, or Mann.  In those cases you can buy the exact same part for less, retail, than the OEM VW part because it didn't come in a VW box.  VW and Audi part numbers will always look like the groupings found on this page.

Understanding Audi and VW part numbers

The modern Volkswagen Auto Group (VAG) part numbering system is organized into 5 possible sets of letters and numbers.  Part numbers are normally in sets of 3: 058 133 843 (the air filter mentioned earlier) but sometimes they come in sets of up to 5 like this: 3d0 601 025 p 8z8.  The 5 set is just 3 set with 2 optional codes so I'll use that as an example.  It's a 19" alloy wheel model "omanyt" off a VW Phaeton.  I try to type the part number letters in lower case so that it's harder to confuse 0 and O, 8 from B, and so forth.  One exception is L: the lower case l and 1 are too similar.

# 3d0 601 025 p 8z8

Set1 3d0
The first two digits are the specific model (chassis code) the part goes on.  Sometimes it's for a specific engine or transmission and sometimes these parts are shared across models.  The chassis code can be found in the 7th and 8th digit of the car VIN.  In this example 3d means it's from a VW Phaeton.  The chassis codes can be found at the bottom of the page (they take up too much space here.  The third digit shows if the part is different on left hand drive cars (LHD) or right hand drive cars (RHD).  If it's 0 there's no difference.  If it's 1 it's for LHD and if it's 2 it's for RHD.  In this example wheels can go on both sides so it's 0.

Set2 601
The fourth digit is the main group.  This corresponds to what ETKA section and illustration you can find the part in.  In this example it's a wheel so the main group is 6: Wheels, Brakes (shown below in the ETKA screenshot).  (Dealer accessory wheels are considered extras so they're found in main group 0.)  The main groups are:
1 – engine, clutch (ie, turbo, timing belt, air/fuel filters)
2 – gastank and pipelines, exhaust system, heater
3 – transmission
4 – front axle, differential, steering (ie., front suspension)
5 – rear axle
6 – wheels, brakes
7 – hand and footlevers, safety covers (ie., pedals and shifter)
8 – body
9 – electrical systems (ie., v-belt, starter, ignition, instrument cluster)
0 – extras (ie., optional parts, radio, and optional wheels)

The fifth and sixth digit are the subgroup.  At the top of the screenshot you can see "SG" for subgroup 01.  In this example, main group 6's subgroup 01 is wheels.  This is also shown in the column of labeled "MG, SG, Ill-NO." on the right.  There are too many to list but as another example, main group 6's subgroup 15 is disc brake.  98 is always repair kits.

Set3 025
Digits seven, eight, and nine are random numbers.

Set4 p
This is a version or revision code.  In this example it's "p".  If it's included it's usually one or two letters.  Sometimes a revised part comes out or it's slightly different on models with different engines.  A newer version doesn't mean the old version isn't the newest one that will work on your car.  They will use a, b, c., etc., but also skip letters.  Sometimes they name them aa, ab, ac, etc.  Usually the newer part has a later letter.  If it's "x" it means the part is rebuilt.

Set5 8z8
This is a color code.  In this example the wheel is 8z8 or "brilliant silver".  If it's included it can be a mix of letters or numbers.  This is often found on interior trim and seats since there are so many color combinations.  "gru" always means means primered or ready to paint.

Have any question about the part numbering system for VAG cars?  Do you see an error?  Did you think ETKA was ekta?  You can search the site for more or ask in the discussion forums here: myturbodiesel.com forums

VAG chassis codes
Here are the chassis codes that are the first two digits of set1.