LCGM51
Radio Replacement Interface for General Motors Vehicles
Pacic Accessory Corporation
® | Clearwater, Florida 33760 | Ph. 866-931-8021 | support@pac-audio.com 
©2015 Pacic Accessory Corporation
www.pac-audio.com
Rev. 012915
The LCGM51 allows the replacement of a factory radio in select General Motors vehicles with 29-bit v2 GMLAN radios. Using this 
interface will retain factory features such as warning chimes and provides a data-bus generated 12-volt retained accessory power 
output (RAP). RAP keeps the radio powered after key-off, just like the factory system. The LCGM51 also issues data commands 
that maintain a “healthy” system status to other vehicle systems.
Introduction & Features
Installation Steps
PLEASE NOTE: This Interface is intended 
for  use  in  vehicles  without  OnStar®  or 
Bose®  or  when  OnStar®  or  Bose®  does 
not need to be retained.
1.  Wire your aftermarket radio to the LCGM51 harness 
according  to  the  wiring  connections  chart.  The 
red accessory wire will support up to 10 amps  of 
current draw. 
2.  Remove the factory radio and plug in the LCGM51’s 
14/16-pin harness into the factory vehicle harness. 
Using  the  supplied  length  of  wire,  mount  the 
interface within the dash of the vehicle with double 
sided tape or wire ties. There are no  adjustments 
to make, just mount your aftermarket radio and re-
install your factory dash panels and you’re done! 
1.  Turn  the ignition on. The LED on the interface will turn on & the +12v accessory wire will turn on.
2.  Turn on the radio & check balance & fade.
3.  Turn off vehicle & remove key. RAP will be active & keep the radio on for 10 minutes or until the drivers door is opened.
4.  The LED & radio will turn off when RAP turns off or the drivers door is opened.
Testing & Verication
Illustration / Schematic
Yellow Battery +12v
Black Ground
Red Accessory +12v 
(10A)
White Front L + input
White / Black Front L - input
Grey Front R + input
Grey / Black Front R - input
Green Rear L + input
Green / Black Rear L - input
Purple Rear R + input
Purple / Black Rear R - input
Wiring Connections