Decoding your J-body's VIN Number
Modern Vehicle Identification Number systems are based on two related standards originally issued by the ISO in 1979 and 1980, ISO 3779 and ISO 3780, respectively. Compatible, but somewhat different, implementations of these ISO standards have been adopted by the European Union and the United States of America.
The rest of this article is specific to GM J-Body cars. :)
World Manufacturer Identifier
The first three characters uniquely identify the manufacturer of the vehicle using the World Manufacturer/Make Identifier (WMI) code.
The 1st position in the VIN indicates the Country in which the vehicle was manufactured.
1,4 = United States
3 = Mexico
The 2nd character in the VIN identifies the Manufacturer; a J-Body VIN is always a "G" for General Motors.
G = General Motors
The 3rd character identifies the Make, and is used by GM as a code for its divisions.
1 = Chevrolet
2 = Pontiac
3 = Oldsmobile, Toyota
4 = Buick
6 = Cadillac
Here are some examples you will find on J-Body cars:
1G1 = Chevrolet passenger car built in the US
3G1 = Chevrolet passenger car built in Mexico
1G2 = Pontiac passenger car built in the US
3G2 = Pontiac passenger car built in Mexico
4G1 = Chevrolet passenger car built in the US
Here's a special one you might see if you happen to see a Toyota Cavalier:
4G3 = Toyota passenger car, built in the US for export to Japan
Vehicle Descriptor Section
The 4th through 9th positions in the VIN are the Vehicle Descriptor Section (or VDS). This is used to identify the vehicle type and includes information on the platform used, the model, and the body style.
The 4th position indicates the Carline, and is always a "J" to indicate a J-Body platform car. Note that the Saturn L200 and L300 also have a J in the 4th position, but are not considered to be J-body cars.
The 5th position indicates the Series of vehicle:
Buick
S = SkyHawk
T = SkyHawk Limited
E = SkyHawk T-Type
Cadillac
G = Cimarron
Chevrolet
C = Cavalier
D = Cavalier CS
E = Cavalier Hatchback/Type 10/RS
F = Cavalier Z24/LS
H = Cavalier Z24 (export)
Oldsmobile
C = Firenza
D = Firenza SX/LX
Pontiac
B = J2000, 2000, 2000 Sunbird, Sunbird, Sunfire
C = J2000 LE, 2000 LE, 2000 Sunbird LE, Sunbird LE
D = J2000 SE, 2000 SE, 2000 Sunbird SE, Sunbird SE, Sunfire GT
E = J2000 S
The 6th position indicates the Body Style.
1 = Two door coupe (37)
3 = Two door convertible (67)
5 = Four door sedan (69)
8 = Five door station wagon
The 7th position indicates the Restraint Type.
1 = Active (manual) seatbelts
2 = Active (manual) seatbelts with driver and passenger front airbags
4 = Automatic seatbelts
The 8th position indicates the Engine Type. Some of the engines found in J-Body cars include the following:
4 = 2.2L Inline 4 SFI (LN2) aka 2.2L OHC, 2200, "Not an Ecotec" (92-02)
F = 2.2L Inline 4 MFI (L61) aka "Ecotec" (02-05)
D = 2.3L Inline 4 MFI (LD2) aka "Quad 4" (95 only)
T = 2.4L Inline 4 SFI (LD9) aka "Twin Cam" (96-02)
J = 3.1L V6 SFI (LG8)
W = 2.8L V6
G = 1.8L Inline 4 (82 only)
O = 1.8L Inline 4
B = 2.0L Inline 4
P = 2.0L Inline 4
1 = 2.0L Inline 4
K = 2.0L Inline 4
M = 2.0L Inline 4
H = 2.0L Inline 4
G = 2.2L Inline 4 (90, 91)
The 9th position is known as the Check Digit. A mathematical formula is used to determine the value of the check digit, based on the other characters in the VIN. How the check digit is calculated is not a secret (you can find it on the internet easily if you Google search) but is not covered in this FAQ article.
Vehicle Identifier Section
The 10th through 17th positions are used as the Vehicle Identifier Section or VIS.
The 10th character is used to encode the model year of the vehicle. The year code is the model year allocated by GM, not the year in which it was manufactured.
Example: an "early 2002" model year car would be manufactured in the middle of the 2001 calendar year, but will still have the number 2 in the 10th position indicating 2002. Note that some other manufacturers use this to indicate the calendar year in which the vehicle was built as opposed to the model year... but GM does not... and this is the GM J-Body FAQ :)
C = 1982
D = 1983
E = 1984
F = 1985
G = 1986
H = 1987
J = 1988
K = 1989
L = 1990
M = 1991
N = 1992
P = 1993
R = 1994
S = 1995
T = 1996
V = 1997
W = 1998
X = 1999
Y = 2000
1 = 2001
2 = 2002
3 = 2003
4 = 2004
5 = 2005
The 11th character indicates the assembly plant the vehicle was manufactured in.
M = Lansing, Michigan
7 = Lordstown, Ohio
B = Lansing, Michigan (Genasys convertible plant)
S = Ramos Arizpe, Mexico
C = South Gate, California (82 only)
J = Janesville, Wisconsin
K = Leeds, Missouri
The 12th to 17th positions indicate the Production Sequence Number. This is used to identify the individual vehicle in question. This is a simple sequential number. Cavaliers usually start with the number 000001, Sunfires with the number 500001.
