1GK

The first three characters of every VIN are the World Manufacturer Identifier (WMI). The code 1GK is assigned to GMC, with the country of manufacture United States.

So any 17-character VIN that begins with 1GK was produced by GMC:

1GKZZZ0000000000000

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.