GM Service Manual Online
For 1990-2009 cars only

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

1999

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