"GM VIN decoder" is one of the more confusing searches in this space, because General Motors isn't a single brand. It's a holding company for four active US brands (Chevrolet, GMC, Buick and Cadillac) plus several discontinued ones (Pontiac, Saturn, Hummer), and every one of them has its own world manufacturer identifier. Decoding a GM vehicle means decoding it as the specific brand, not as "GM".
GM's WMI blocks, brand by brand
| Brand | Common WMI prefixes | Status |
|---|---|---|
| Chevrolet | 1G1, 1GC, 1GB, 1GN, KL1, KL8 | Active |
| GMC | 1GT, 1GK, 1GD | Active |
| Buick | 1G4, 5GA, KL4, LRB | Active |
| Cadillac | 1G6, 1GY, 3G0 | Active |
| Pontiac | 1G2, 6G2 | Discontinued 2010 |
| Saturn | 1G8 | Discontinued 2010 |
| Hummer | 5GR | Discontinued 2010 |
The pattern that actually matters: the second character "G" across nearly all of these blocks marks General Motors as the corporate manufacturer of record. The first character gives the country (1 is the United States, 2 is Canada, 3 is Mexico, K is South Korea), and the remaining characters narrow it down to the specific brand and vehicle class.
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Why there's no single "GM decoder" page
Model names, engine descriptor codes and safety-equipment fields (VIN positions 4 through 8) are filed separately by each GM brand with NHTSA, even when two vehicles share a platform. A Chevrolet Tahoe and a GMC Yukon come off the same assembly line in Arlington, Texas on the same platform, but they carry different WMIs and different position 4-8 codes because they're filed as separate products. Decoding either one correctly starts from the actual VIN, not from assuming "GM" as the brand.
GM built outside the United States
GM Korea (formerly Daewoo) supplies several Buick and Chevrolet models sold in North America, which is why KL1 (Chevrolet Spark, Trax) and KL4 (Buick Encore) show up on cars badged as American brands. LRB marks the Buick Envision, built in Yantai, China, one of the few Chinese-assembled vehicles sold under a US badge. None of this is a decoding error, it reflects where GM actually builds each model.
Decode by the actual brand
Pick the page that matches the badge on the vehicle. Each one has the full WMI table, assembly plants and a decoder that returns the factory build sheet plus open recalls:
Chevrolet VIN decoderGMC VIN decoderBuick VIN decoderCadillac VIN decoder
Frequently asked questions
Is there an official GM VIN decoder?
No single one. General Motors files each brand (Chevrolet, GMC, Buick, Cadillac) separately with NHTSA, so you decode by brand. The federal vPIC database behind all of them is the same, only the WMI and model-specific fields differ.
Why do a Chevy Tahoe and GMC Yukon have different VIN prefixes if they're the same truck?
Even though they share a platform and often an assembly line, Chevrolet and GMC are filed as separate manufacturers with NHTSA, so each brand gets its own WMI block and its own position 4-8 descriptor codes.
What does a VIN starting with KL mean on an American car brand?
KL is the South Korea region code. GM Korea (formerly Daewoo) builds several Chevrolet and Buick models sold in the US, including the Spark, Trax and Encore, so a KL-prefixed VIN on one of those is normal.