THIS PACKAGE FITS THE FOLLOWING VEHICLES: 
 
Chevrolet:
2000-2005 Impala
2000-2005 Monte Carlo
2002-2007 Trail Blazer (SLE)
2002-2004 Trail Blazer (SLT) *
2002-2007 Venture
2002-2007 Uplander
2003-2006 Tahoe
2003-2006 Suburban
2003-2006 Silverado
2003-2006 Avalanche
2003-2006 SSR *
2005-2008 Corvette
2005-2008 Colorado
2007 Silverado (Classic)
GMC:
2002-2007 Envoy (SLE)
2002-2004 Envoy (SLT) *
2002-2007 Montana
2003-2006 Yukon
2003-2006 Sierra
2003-2006 Denali (Sierra and Yukon) *
2005-2008 Canyon
2007 Sierra (Classic)
Buick:
2002-2007 Rainier
2002-2007 Terraza
2003-2006 Bravada
Pontiac:
2004-2007 Grand Prix
Cadillac:
2003-2006 Escalade *
Hummer:
2003 H2 *
2005-2008 H3
--------------------------
PAC  OS-2C
OnStar Interface (OS2C) for Select 2000-2008 GM Vehicles
GENERAL FEATURES:
Chime Module Included
Retains OnStar® when the factory radio is replaced
Retains Bose amplified audio system
Retains all safety warning chimes
Maintains a "healthy" status on the Class II databus
Plug-in installation for vehicles with 24-pin harness
 
Compatibility
In "Premium" Amplified Systems only two input channels can be used from the aftermarket radio, therefore there will be no fading capability of the aftermarket stereo.
The CM-1 Chime Module is not required when used in conjunction with a Premium BOSE® amplifier. 
If you are not using the BOSE® amplifier, then the OS-2 and CM-1 modules are required.
Not compatible with 2009 vehicles that are equipped with O.E.M. Bluetooth.