GM1A-R
Introduction and Features
The GM1A-R interface allows the replacement of a factory radio in select General Motors vehicles with the Class II Data-Bus.
Using this interface will retain factory features such as warning chimes and the factory Bose amplifier when the original radio is
removed. The GM1A-R provides data-bus driven outputs such as retained accessory power (RAP), vehicle speed signal (VSS),
illumination, reverse trigger and parking brake. The GM1A-R also provides an SWI Direct output for adding an optional PAC
Steering Wheel Control (SWC) retention interface (SWI-RC or SWI-CP2). Rear Seat Controls (RSC) if equipped will also be
retained with the SWI interface.
Important Notes
1. Does not retain OnStar.
2. Does not provide RSE audio to aftermarket radio.
3. Compatible in both Premium (Y91 / UQA) and Standard Bose systems.
4. The Programming Button and Adjustment Dial on the side of the interface have multiple functions. Please see Page 2 for
more details.
Module Layout
Interface
Connector 2
Interface
Connector 1
Installation Steps
1. Wire your aftermarket radio to the GM1A-R's harness according to the wiring
connections chart. In vehicles without a Bose system: Cut the resistor packs
wrapped in heat shrink off and connect the aftermarket radio's speaker outputs
to the remaining wires according to the wiring connections chart. Vehicles with
a Bose system: Wire the GM1A-R harness up as-is, with the resistor packs in
the harness.
2. Plug Interface Connectors 1 and 2 into the appropriate port on the GM1A-R
interface (using the illustrations above or the label on the bottom of the interface).
3. If you are also installing an optional SWC interface with the GM1A-R, connect the
SWI Direct Connector to the SWC interface. (Please refer to the SWC interface
instructions for configuration and programming instructions).
4. Remove the factory radio and plug in the GM1A-R's vehicle harness into the
factory vehicle harness.
5. If necessary, program the SWC interface. Please see next section for more
details.
Interface Connector 1 Interface Connector 2
Pacific Accessory Corporation
Adjustment Dial
© 2018 AAMP Global. All rights reserved. PAC is a Power Brand of AAMP Global.
PAC-audio.com
LED 2
LED 1
Programming
Button
Vehicle Connector
Radio Replacement Interface
for select General Motors Vehicles
with Class II Data-Bus
USB Port
Wiring Connections
Yellow
12v+
Accessory Output
Red
(10 amp)
Black
Ground
Blue / White
Remote On Input
Orange
Not Used
Orange / White
Illumination Output
Purple / White
Reverse Output (+)
Light Green
Parking Brake Output (-)
Vehicle Speed Signal
Pink
Output (VSS)
Purple
Rear R + input
Purple / Black
Rear R - input
Green
Rear L + input
Green / Black
Rear L - input
Gray
Front R + input
Gray / Black
Front R - input
White
Front L + input
White / Black
Front L - input
Rev: V7
Date: 072418
Page 1
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