GM6A-RST

Introduction and Features

The GM6A-RST interface allows the replacement of a factory radio in select General Motors vehicles with 29-bit LAN v2, 20-pin and 16-pin connector radios. Using this interface will retain factory features such as BOSE, OnStar, vehicle settings, steering wheel controls (SWC), front and rear park assist and warning chimes when the original radio is removed. The GM6A-RST also provides data bus driven outputs such as retained accessory power (RAP), vehicle speed (VSS), illumination, reverse trigger and parking brake.

Important Notes

1. Please make your vehicle settings selections before removing the factory radio for optimal installation time. Once the radio has been removed, the vehicle settings which are normally selected through the factory radio can be accessed and changed by downloading and installing the PAC RadioPRO PC Application from http://www.pac-audio.com/firmware.
2. Before removing your factory radio, please review the following settings as these will not be retained once the factory radio is removed:
   • Ambient Lighting Control
   • Teen Driver Feature
   • Valet Mode
   • Rear Park Assist Symbols displayed on Reverse Camera Image
   • OnStar Text
   • Performance Data Recorder
   • Custom Launch Control (Line Lock, Launch Control)
3. When you plug in the module for the first time, it must go through an initialization process that takes up to 12 seconds. Make sure you have the vehicle running during this process.
4. The radio select dip-switchs on the side of the interface must be adjusted to the proper radio setting before plugging the interface into the vehicle (see page 2 for setting chart).
5. The Voice button can be set to activate the factory OnStar function by using the RadioPRO PC Application. By default, this button is re-programed to control the aftermarket radio's voice function.
6. The interface comes pre-programmed for all of the vehicles factory SWC functions and does not require programming unless you wish to re-assign the SWC functions, utilize the buttons that have no initial programming or utilize short press long press dual command functionality. The SWC can always be restored to default settings by pressing and releasing the program button on the side of the interface once and waiting 7 seconds for the LED to flash 4 times.
   • Chevrolet Malibu will require SWC re-mapping. By default volume up / down and track up / down are reversed.
7. The VS41 can be added to control Rear, Front, Left, Right cameras through the interface. See Page 5 for details.
8. Language: In some vehicles the language setting is controlled over MOST. Please make sure that you adjust this accordingly before removing the radio as this will not show up in most cases after your install.
9. For Referencing (IO) Codes. Please refer to the vehicles RPO CODE sticker normally located in the vehicles glove box or the underside of the spare tire cover.

Module Layout

The module features several key components:

• Adjustment Dial: Used for various settings and volume adjustments.
• Programming Button: Used for programming SWC and accessing modes.
• Interface Connector 4: A 24-pin connector.
• Expansion Port: For connecting additional modules like the VS41.
• Radio Select DIP switches: Used to configure the interface for different aftermarket radios.
• USB Port: For connecting to the RadioPRO PC Application.
• Non-Amplified Audio Output: Connects to non-amplified audio systems.
• Amplified Audio Output: Connects to amplified audio systems.
• LED 1 & LED 2: Status indicator lights.
• Interface Connector 1: A 3-pin connector.
• Interface Connector 2: A 20-pin connector.
• Interface Connector 3: A 12-pin connector.

Diagram Description: The diagram shows the top view of the GM6A-RST interface with labels pointing to the Adjustment Dial, Programming Button, Interface Connector 4, Expansion Port, Radio Select DIP switches, USB Port, Non-Amplified Audio Output, Amplified Audio Output, LED 1, LED 2, Interface Connector 1, Interface Connector 2, and Interface Connector 3.

Installation Steps

DIP Switch Settings

Set DIP switches that correspond with your radio to the ON position. Set all other DIP switches to the OFF position.

If your brand is not listed above, please use "ALL OTHER BRANDS."

Connection Procedure

1. Set the Radio Select DIP switches according to the radio you are installing.
2. Wire your aftermarket radio to the GM6A-RST's harness according to the wiring connections chart on Page 3.
3. Cut the Brown mute loop in Interface Connector 4. If not cut, it will turn the GM6A's accessory output off when any OnStar function is active.
4. Plug Interface Connectors 1 & 2 into the appropriate ports on the GM6A-RST interface (using the diagram on page 1 or the label on the bottom of the interface).
5. The Interface Connector 3 connection port will be dependent upon whether or not the vehicle has a factory amplified system. Plug this connector into the appropriate port on the GM6A-RST (using the diagram on page 1 or the label on the bottom of the interface).
6. Remove the factory radio and plug in the GM6A-RST's Vehicle Connector 1, 2, & 3 into the factory vehicle harness. Vehicle Connector 3 might not be present in all vehicles. In vehicles with IOA / IOB, use Vehicle Connector 7 to adapt your main harness to your vehicle.
7. Vehicle Connectors 4 & 5 are used when removing the factory CD player in the dash and are mandatory that they are plugged in to keep the MOST loop intact. Failing to plug these in will result in no sound. Not all connectors may be present.
8. Vehicle Connector 6 (GM5CAM-DIS-HAR) will only be used in vehicles with an IOB Build Code and will be connected to the harness that was plugged into the factory display once removed. This is used to maintain the camera signal in IOB build code vehicles.

Diagram Description: The page displays diagrams of various interface connectors (Interface Connector 1 (3-pin), Interface Connector 2 (20-pin), Interface Connector 3 (12-pin), Interface Connector 4 (24-pin)) and vehicle connectors (Vehicle Connector 1 (20-pin), Vehicle Connector 2 (16-pin), Vehicle Connector 3 (8-pin), Vehicle Connector 4 (10-pin), Vehicle Connector 5 (12-pin), Vehicle Connector 6 (20-pin), Vehicle Connector 7 (Adapter)).

Wiring Connections Chart

Aftermarket Radio Connections

IMPORTANT NOTES REGARDING GREEN / BLACK WIRE CONNECTIONS*

There is a 60" Pigtail that is used for connecting the SWC input to the GM6A module that has a bullet connector on one end, and a loose wire on the other. This is designed to plug into the matching bullet connector on the GM6X-HAR; both of which have a matching SWC Input label.

Wiring Connections (Continued)

1. Make all connections as described in the chart above. Be sure to review all connections before plugging the harness into your vehicle.
2. In vehicles with an IO5 / IO6 RPO CODE, to retain the steering wheel control buttons you must hardwire them into the GM6A-RST. The wire you need to connect into can be found by removing the steering wheel shroud located beneath the steering wheel column, and accessing the wire in pin 9 at the Black 10-pin connector located at the base of the clock spring. (See Fig. 1).

   Once you have located the Green/Black wire in the vehicle, you must connect the provided 60" Green/Black wire from the GM6A module. This is a data signal, so to ensure consistent operation, it is highly recommended to solder this wired connection. DO NOT cut this wire in half. In some vehicles, it may be necessary to remove the cover around the steering column and tag the wire in pin 9 at the Black 10-pin connector located at the base of the clock spring.

   Diagram Description (Fig. 1): Shows a close-up of a steering wheel column wiring harness, highlighting a black 10-pin connector and indicating a specific wire (pin 9) for connection.

3. Plug the chime speaker module in if needed. It is only necessary if you are connecting an aftermarket amplifier to the cabin speakers. Connect the chime speaker to the chime plug coming out of Interface Connector 3 and install the chime speaker in a place free of obstructions, where it can be easily heard (usually low in the dash facing downward).
4. Connect the SWC wire or the 3.5mm SWC jack to the aftermarket radio according to the chart above (aftermarket radio MUST support a wired remote input).
5. If you wish to reassign functions to the SWC, then follow the programming instructions on page 5.
6. Connect the Red and White RCAs to the aftermarket radio's AUX input to retain the factory 3.5mm AUX input jack.
7. If the vehicle was equipped with the base level radio (IO3) and a factory reverse camera, then connect the Yellow RCA in the harness to the reverse camera input on the back of the radio. If your vehicle is equipped with the IO4, IO5 or IO6 system, follow notes "A & B" below for reverse camera retention. Please reference the vehicles RPO CODE sticker normally located in the vehicles glove box or the underside of the spare tire cover. Please disregard the Yellow RCA on the main GM6X-HAR when using the CAM-GM51.
   • A. Connect the supplied CAM-GM51 Harness (See Fig. 2). The CAM-GM51 harness connects at the Human Machine Interface Control Module (HMICM), not at the radio. The HMICM is normally found behind the glove box in trucks and SUVs, or high in the passenger side kick panel area in other vehicles. The (HMICM) will have the USB and LVDS cables connected to it. (Pictured Below)
   • B. The factory reverse camera is powered by the vehicle, not the HMICM. The camera will continue to be powered even when disconnected from the HMICM, so no additional wiring is required to supply the camera with power.

   Diagram Description (Fig. 2): Shows the CAM-GM51 harness and its connection point at the HMICM, which is described as being behind the glove box or in the passenger side kick panel.

Programming Button and Adjustment Dial Functions

You can press and hold the programming button on the side of the interface to access different programming modes. Once the LED is lit to the mode you desire (see below for modes), immediately release the programming button to access that mode.

PLEASE NOTE:

• This process must be done with the interface in the vehicle and the key in the ignition position.
• If there is a Bose system, and you are also installing an amplifier on the cabin speakers, make sure that the included chime speaker is connected.

Programming Modes:

• A. LED 1 flash green: SWC re-assignment. This allows you to re-assign the SWC functions to the buttons of your choice. Please see the Optional Steering Wheel Control Programming instructions below for more details.
• B. Both LEDs flash green: Chime volume adjustment. This allows you to adjust the volume of the chimes using the adjustment dial on the side. Please see note 6 under Testing and Verification for more details.
• C. Both LEDs flash red: Master reset. This does a master reset of the interface and restores the following settings to factory defaults:
  • SWC Mapping
  • Camera Settings
  • Infotainment Settings
  • Interface User Options

Default Steering Wheel Control Programming

Default SWC Button Assignments

Optional Steering Wheel Control Programming

Programming Steps:

1. Turn the key to the ignition position.
2. Press and release the programming button on the side of the interface.
3. Within 7 seconds, press the button that is to be learned on the steering wheel. LED 1 will turn red when the button is pressed. At this point you have two options:
   • A. For short press functionality: Release the button within 1.5 seconds. LED 1 will turn back to green.
   • B. For long press functionality: Hold the button until LED 1 starts blinking. Release the button and the LED will go back to green.
4. Repeat step 3 for each additional audio function on the steering wheel.
5. If you come across a function in the chart that your steering wheel does not have, or you do not want to program, press and release the programming button on the side of the interface to skip that function.
6. Once programming is completed, wait seven seconds and LED 1 will flash three times indicating that programming has finished.
7. Test the interface for proper functionality. Whenever a button on the steering wheel is pressed, LED 1 will illuminate green.
8. If any function does not work, repeat the programming steps.

Optional Steering Wheel Control Programming (cont.)

Optional Programming Order

If your brand is not listed above, please use "ALL OTHER BRANDS." Please Note: On any entry with multiple commands, the commands shown are source dependent.

VS41 Operation and Functionality

The VS41 connects to the 10-pin Expansion Port which is located on the side of the RadioPRO interface, See Page 1. This system works by using your vehicle's data system to trigger appropriate cameras when needed and will allow for up to 4 camera inputs.

• The RadioPRO will digitally control the VS41 switching operation when connected to the Expansion Port. Be sure to insulate the end of all unused wires on the VS41 harness. The positive or negative trigger wires in this application will only be used if you are using a camera that is labeled AUX in the RadioPRO PC application.
• The Reverse Trigger from the VS41 Module (Purple/White) output will provide a 150 mA 12v (+) trigger while any of the input triggers are activated. The (Purple/White) from the GM6A will need to be wired into (Input 1 Trigger +) for the Reverse camera to work properly. The VS41 video output will always default to Video 1 Input when none of the input triggers are activated. This Input is ideal for connecting your (reverse) camera for normal operation.

Diagram Description: The VS41 diagram shows connections for Video Output, Video 1-4 Inputs, Input 1-4 Triggers (positive and negative), Reverse trigger output, Accessory 12v, Ground, and the 10-Pin Plug for the Expansion Port. It also illustrates how to connect to the Purple/White wire of the GM6A-RST and use it to trigger cameras labeled AUX. It notes not to use Yellow/Black wires and to insulate them.

RadioPRO PC App

Download the RadioPRO PC App at: https://pac-audio.com/app-downloads/

Use of the RadioPRO PC App allows you to do the following:

• Configure User Interface Options such as:
  • Factory amplifier settings
  • Chime Volume
  • Camera Settings
  • Telematics Volume
• Change Vehicle Settings
• Update Product Firmware
• Read Firmware/Hardware Versions

PLEASE NOTE:

The interface must be connected to the vehicle when using the following features of the RadioPRO PC App:

• Factory Amplifier Settings
• Chime Volume
• Telematics Volume
• Change Vehicle Settings
• Interface User Options
• Camera Settings

The interface does not need to be connected to the vehicle when using the following features of the RadioPRO PC App:

• Firmware Updates
• Reading firmware/hardware versions

OnStar Volume Adjustment for Vehicles without SWC

1. If SWC buttons are not present, you must use the Adjustment Dial on the side of the interface until the desired level is reached.
2. When OnStar is active, turn the Adjustment Dial on the side of the interface until the desired level is reached.

Testing and Verification

1. Turn the ignition on. The LED on the interface will turn on and the +12v accessory wire will turn on.
2. Turn on the radio and check balance and fade.
3. Pressing the OnStar button on the rearview mirror will turn off all audio and allow the OnStar audio to be heard.
4. Verify that all SWC are functioning properly for both the aftermarket radio and OnStar. To adjust OnStar volume, press the OnStar button on the mirror or steering wheel, then use the volume buttons on the SWC to adjust the level. If the vehicle is not equipped with steering wheel controls, you can use the adjustment dial to raise the volume of the OnStar.
5. Verify that chimes are functioning. Chimes will play out of the front left speaker. If you have an aftermarket amplifier on your speakers, chimes will play out of the supplied RPA-SPK chime speaker.
6. If you need to adjust the volume of the chimes: With the vehicle on, press and hold the programming button until both LEDs flash green, then release. Now turn the dial on the side of the module to adjust volume. If no BOSE amp, you will hear an audible chime during adjustment. If there is a BOSE amp, there is no audible chime and you have to do a sleep cycle to hear the change. Chime adjustment mode will time out after 10 seconds of inactivity.
7. Turn off vehicle and remove key. RAP will be active and keep the radio on for 10 minutes or until the driver's door is opened.

Technical Support and Product Updates (Firmware)

The GM6A-RST can be updated with new firmware as it becomes available using a USB cable and RadioPRO PC application. Please visit www.PAC-audio.com/firmware for available updates.

Email: support@PAC-audio.com

Standard / International: 727-592-5991