For 1990-2009 cars

All engines and transmissions are stamped or laser etched with a partial Vehicle Identification Number (VIN), which was derived from the complete VIN. A VIN derivative contains the following nine positions:

Position | Definition | Character | Description
--- | --- | --- | ---
1 | GM Division Identifier | 2 3 4 | Pontiac Oldsmobile Buick
2 | Model Year | W | 1998
3 | Assembly Plant | H 4 | Buick City Lake Orion
4-9 | Plant Sequence Number | -- | --

A VIN derivative can be used to determine if a vehicle contains the original engine or transmission, by matching the VIN derivative positions to their accompanying positions in the complete VIN:

VIN Derivative Position | Equivalent VIN Position
--- | ---
1 | 3
2 | 10
3 | 11
4-9 | 12-17