In 1985, GM first introduced VATS
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 has 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.

ALLANTE 1989-1993
AURORA 1995-1999
BONNEVILLE 1992-1999
BROUGHAM FLEETWOOD 1993-1995
Buick
CADILLAC
CAMARO 1989-2002
CAPRICE 1995-1996
Century & S/W 1997-2004
CHEVROLET & GMC
CONCOURS DEVILLE 1991-1999
CORVETTE 1986-2004
CUTLASS SUPREME 1994-1997
EL DORADO 1989-2002
FIREBIRD, FORMULA, GTA 1989-2002
GRAND PRIX 1994-1996
GTA ONLY FIREBIRD 1988
IMPALA 1995-1996
LeSABRE 1992-1999
LUMINA SEDAN & COUPE 1994-2000
MONTE CARLO SEDAN & COUPE 1994-1999
OLDSMOBILE
PARK AVENUE 1991-1996
PONTIAC
REATTA 1990-1991
REGAL 1997 1/2-2004
REGENCY 1998
88, 88 REGENCY 1991-1996
RIVIERA 1992-1999
ROADMASTER 1994-1996
88, 88 ROYAL, LSS 1992-1999
SEVILLE 1991-1997
TORANADO 1990-1992
ULTRA 1991-1996