GM first introduced VATS in 1985 on the Chevrolet Corvette, and after proving successful, was later introduced in other models in later years. Operation is fairly simple, The most obvious part is the key. The ignition key as a little "chip" in it. This is a resistor "pellet". There are 15 possible resistances, therefore 15 different types of keys each with a different resistance. This reduces the likelihood of a potential thief from having the correct resistance resistor on hand. Then you have to have a special lock cylinder to "read" the key. Next is the VATS module, It is the "brains" of the system. The module is what actually "MEASURES" the resistance, but has to do it via the contacts in the lock cylinder and the related wiring. Think of the module as a Multimeter, and the wires and contacts the Multimeter Leads. The module reads the resistance and determines if the resistance is the correct value before the vehicle will start.

Buick

Century & S/W 1997-2004

LeSABRE 1992-1999

PARK AVENUE 1991-1996

ULTRA 1991-1996

RIVIERA 1992-1999

REATTA 1990-1991

REGAL 1997 1/2-2004

ROADMASTER 1994-1996

CADILLAC

ALLANTE 1989-1993

BROUGHAM FLEETWOOD 1993-1995

CONCOURS DEVILLE 1991-1999

EL DORADO 1989-2002

SEVILLE 1991-1997

CHEVROLET & GMC

CAMARO 1989-2002

CAPRICE 1995-1996

CORVETTE 1986-2004

IMPALA 1995-1996

LUMINA SEDAN & COUPE 1994-2000

MONTE CARLO SEDAN & COUPE 1994-1999

OLDSMOBILE

AURORA 1995-1999

CUTLASS SUPREME 1994-1997

88, 88 ROYAL, LSS 1992-1999

REGENCY 1998

88 REGENCY 1991-1996

TORANADO 1990-1992

PONTIAC

BONNEVILLE 1992-1999

FIREBIRD, FORMULA, GTA 1989-2002

GRAND PRIX 1994-1996

GTA ONLY FIREBIRD 1988