GMC VIN decoder
What each part of a GMC VIN means, from real GMC VINs on file with NHTSA.
GMC VINs start with a World Manufacturer Identifier (WMI) such as 3GT (Mexico), 1GT (United States) and 1GK (United States); these are the most common on 3,870 GMC VINs in NHTSA complaint records for the models VinSnap tracks. Position 10 is the model year (M = 2021, N = 2022 and R = 2024), position 9 is a check digit, and positions 4–8 describe the model, body and engine. Enter a full VIN in the VinSnap decoder to see the exact model, trim and engine.
Last updated: · Source: NHTSA vPIC and complaint VIN records
GMC WMI codes (VIN positions 1–3)
| WMI | Built in | Registered manufacturer | Vehicle type | VINs seen | Models seen |
|---|---|---|---|---|---|
3GT | Mexico | GENERAL MOTORS LLC | Truck | 1,359 | Sierra, Acadia, Terrain |
1GT | United States | GENERAL MOTORS LLC | Truck | 1,026 | Sierra, Terrain, Acadia |
1GK | United States | GENERAL MOTORS LLC | Multipurpose Passenger Vehicle (MPV) | 699 | Acadia, Sierra, Terrain |
2GK | Canada | GENERAL MOTORS LLC | Multipurpose Passenger Vehicle (MPV) | 440 | Terrain, Acadia |
3GK | Mexico | GENERAL MOTORS LLC | Multipurpose Passenger Vehicle (MPV) | 326 | Terrain |
2GT | Canada | GENERAL MOTORS LLC | Truck | 11 | Sierra |
1GC | United States | GENERAL MOTORS LLC | Truck | 4 | Sierra |
WMIs counted from the first 11 VIN characters NHTSA publishes with owner complaints for the GMC models VinSnap tracks (a WMI needs at least 3 VINs to be listed). Manufacturer and vehicle type from NHTSA vPIC. Country from the ISO 3779 region of the first character.
Model-year code (VIN position 10)
| Model year | Code |
|---|---|
| 2010 | A |
| 2011 | B |
| 2012 | C |
| 2013 | D |
| 2014 | E |
| 2015 | F |
| 2016 | G |
| 2017 | H |
| 2018 | J |
| 2019 | K |
| 2020 | L |
| 2021 | M |
| 2022 | N |
| 2023 | P |
| 2024 | R |
| 2025 | S |
| 2026 | T |
| 2027 | V |
| 2028 | W |
| 2029 | X |
| 2030 | Y |
Letters I, O, Q, U, Z and the digit 0 are never used for the year, so the codes repeat every 30 years (A = 1980 and 2010).
How often the code matches on real GMC VINs in NHTSA complaint records:
| Model year | Expected code | VINs | Match |
|---|---|---|---|
| 2015 | F | 1,334 | 99% |
| 2016 | G | 427 | 100% |
| 2019 | K | 659 | 99% |
| 2020 | L | 289 | 100% |
| 2021 | M | 564 | 100% |
| 2022 | N | 136 | 100% |
| 2024 | R | 461 | 100% |
How the check digit (position 9) works
Each character becomes a number (digits keep their value; letters use the fixed table A=1, B=2 … H=8, J=1 … R=9, S=2 … Z=9), is multiplied by its position weight (8, 7, 6, 5, 4, 3, 2, 10, 0, 9, 8, 7, 6, 5, 4, 3, 2), and the products are added. The remainder after dividing by 11 is the check digit; a remainder of 10 is written as X. A VIN whose position 9 does not match was mistyped or altered.
Worked example with an illustrative VIN 3GTU2VECXRA123456 (a common GMC prefix with a made-up serial — not a real vehicle): the products add up to 340; 340 ÷ 11 leaves 10, so the check digit is X.
| Position | Character | Value | Weight | Product |
|---|---|---|---|---|
| 1 | 3 | 3 | 8 | 24 |
| 2 | G | 7 | 7 | 49 |
| 3 | T | 3 | 6 | 18 |
| 4 | U | 4 | 5 | 20 |
| 5 | 2 | 2 | 4 | 8 |
| 6 | V | 5 | 3 | 15 |
| 7 | E | 5 | 2 | 10 |
| 8 | C | 3 | 10 | 30 |
| 9 | X | 7 | 0 | 0 |
| 10 | R | 9 | 9 | 81 |
| 11 | A | 1 | 8 | 8 |
| 12 | 1 | 1 | 7 | 7 |
| 13 | 2 | 2 | 6 | 12 |
| 14 | 3 | 3 | 5 | 15 |
| 15 | 4 | 4 | 4 | 16 |
| 16 | 5 | 5 | 3 | 15 |
| 17 | 6 | 6 | 2 | 12 |
Frequently asked questions
What does a GMC VIN start with?
The first three characters are the World Manufacturer Identifier. On GMC VINs in NHTSA complaint records the most common are 3GT (1,359 VINs), 1GT (1,026 VINs) and 1GK (699 VINs).
How do I tell the model year from a GMC VIN?
Read position 10: F = 2015, G = 2016, K = 2019, L = 2020, M = 2021, N = 2022 and R = 2024. The same letters repeat every 30 years.
What is the VIN check digit?
Position 9 is computed from the other 16 characters with fixed values and weights, divided by 11; a remainder of 10 is written X. It catches most typing errors.