3G4

The first three characters of every VIN are the World Manufacturer Identifier (WMI). The code 3G4 is assigned to Buick, with the country of manufacture Mexico.

So any 17-character VIN that begins with 3G4 was produced by Buick:

3G4ZZZ0000000000000

The WMI only identifies the maker. To read the year, engine, plant and serial number, decode the complete 17-digit VIN with our free tool — then check which ECU it uses and what tuning services (DPF, EGR, AdBlue, DTC off, Stage) are available.