GM1A-RST

Introduction and Features

The GM1A-RST 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 Steering Wheel Controls (SWC), Rear Seat Control (RSC), OnStar, warning chimes and the factory Bose amplifier when the original radio is removed. The GM1A-RST provides data bus driven outputs such as retained accessory power (RAP), vehicle speed signal (VSS), illumination, reverse trigger and parking brake. You can also add multiple camera inputs to your aftermarket radio with Data-Bus controlled automatic activation (front camera only) by connecting a VS41 into the expansion port on the GM1A-RST.

Important Notes

1. The included chime speaker should be used when: The vehicle has a standard Bose system (UQ7), the vehicle does not have a factory amplifier at all, or if you are connecting an aftermarket amplifier to the cabin speakers.
2. The Programming Button and Adjustment Dial on the side of the interface have multiple functions. Please see Page 3 for more details.
3. Aftermarket radios with a 2-wire resistive based SWC circuit will not have default button assignments programmed. Please refer to the owners manual of the radio you are installing to find out the proper SWC programming procedure.
4. Compatible in both Premium Bose (Y91 / UQA) and Standard Bose systems.
5. Real time speaker fading on Premium factory amplified systems (Y91 / UQA) is only supported with the "amplified output" connection of the GM1A-RST.
6. When using real time speaker fading (Premium Bose only), if the fader setting is biased more to the front or rear, as the radio turns on the sound may begin at the default setting and then quickly transition to your custom setting.
7. Aftermarket radio features such as High Pass Filters (crossovers), DSP or "Network Mode" will interfere with proper fader function (Premium Bose only). In order for the GM1A-RST's fader function to work, the audio from the aftermarket radio's output must match so it can compare the front and rear audio levels and determine the proper fader setting for the factory amplifier.
8. When used in conjunction with the add on camera controller (VS41) the GM1A-RST will only provide Data-Bus controlled automatic activation for the front camera. Please refer to the vehicle specific VS41 instructions for more detail.

Module Layout

The module features an Adjustment Dial and a Programming Button on its side. On the top, there is a USB Port and Radio Select DIP switches. Along the back, there are Interface Connectors 1, 2, and 3, an Expansion Port, Non-Amplified Audio Output, and Amplified Audio Output. Two LEDs (LED 1 and LED 2) are also visible.

Installation Steps

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

*Other - Dual / Axxera (these brands could also have 2-wire resistive), Jensen, Rockford Fosgate

1. Set the Radio Select DIP switches according to the radio you are installing.
2. Wire your aftermarket radio to the GM1A-RST's harness according to the wiring connections chart below.
3. The Brown mute loop in Interface Connector 4 (if not cut) will turn the GM1A's accessory output off when any OnStar function is active. If the aftermarket radio has a mute input, cut this loop and connect the Brown wire in pin 23 to it.
4. Plug Interface Connectors 1 and 2 into the appropriate ports on the GM1A-RST interface (using the diagram on page 1 or the label on the bottom of the interface).
5. The Connector 3 connection will be dependent upon whether or not the vehicle has a factory amplified system. Plug this connector into the appropriate port on the GM1A-RST (using the diagram on page 1 or the label on the bottom of the interface).
6. If the aftermarket radio is equipped with an auxiliary input and you wish to retain the factory RSE audio, plug the RCA connectors from the secondary harness into the radios auxiliary input.
7. Remove the factory radio and plug in the GM1A-RST's Vehicle Connector 1 and Vehicle Connector 2 into the factory vehicle harness.
8. If you wish to reassign functions to the SWC, follow the programming instructions on Page 4.
9. If you are connecting an aftermarket amplifier to the cabin speakers, connect the chime speaker to the chime plug coming out of Interface Connector 4 and install the chime speaker in a place free of obstructions, where it can be easily heard (usually low in the dash facing downward).

Interface and Vehicle Connectors:

• Interface Connector 1 (3-pin)
• Interface Connector 2 (20-pin)
• Interface Connector 3 (12-pin)
• Interface Connector 4 (24-pin)
• Vehicle Connector 1 (24-pin)
• Vehicle Connector 2 (12-pin)

Wiring Connections

VS41 Wiring

The VS41 can be connected to the GM1A-RST and used to switch multiple cameras. Please refer to the document labeled "Instructions for wiring the VS41 into 2003-2006 Chevy / GMC Trucks and SUVs” which can be found on www.pac-audio.com under the VS41 product page.

Adjustable Settings

These products have settings that are adjustable through our RadioPRO PC app or through the push-button on the module. Some settings are only adjustable through the PC app. Some of these settings require the module to be connected to the vehicle. Below is a breakdown of these settings.

Related Downloads

• RadioPRO PC App: http://aampglobal.com/radioproapp
• Latest instruction manuals: Search part number on pac-audio.com, and then look under the "Downloads" tab

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 Premium Bose system, and you are also installing an amplifier on the cabin speakers, make sure that the chime speaker is connected and chimes are enabled through the RadioPRO app before proceeding. Please see the RadioPRO app section on Page 4 for more details.

Programming Modes:

• A. 1 Chime and 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 on Page 4 for more details.
• B. 2 Chimes and LED1 flash amber: SWC re-calibration (this mode is available in the Corvette only). This allows you to re-calibrate the analog SWC in the event they fall out of the expected range and do not function properly. If data control SWC are detected by the interface, this mode will be automatically skipped.
• C. 3 Chimes and both LEDs flash green: Chime volume adjustment. This allows you to adjust the volume of the chimes generated by the interface using the adjustment dial on the side. (This mode is not available in vehicles equipped with Premium Bose (Y91 / UQA) amps. If a premium Bose amp is detected by the interface, this mode will be skipped as the factory amp is what generates the chimes. Please see the vehicles owner's manual for adjustment of chime volume in vehicles with Premium Bose (Y91 / UQA).
• D. 4 Chimes and LED 1 flash red: Master reset. This does a master reset of the interface and restores the following settings to factory defaults:
  • SWC Mapping
  • SWC Calibration
  • Camera Settings
  • Infotainment Settings
  • Interface User Options

Default Steering Wheel Control Programming

Default SWC Button Assignments

*Voice default is OnStar. If OnStar retention is not necessary, unplug the OnStar module to default to Voice (Mute for Fusion radios).

Default SWC Button Assignments (Corvette)

*Voice default is OnStar. If OnStar retention is not necessary, unplug the OnStar module to default to Voice (Mute for Fusion radios).

Optional Steering Wheel Control Programming

Programming

1. Turn the key to the ignition position.
2. Press and release 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 program button on the side of the interface to skip that function.
6. Once programming is completed, wait seven seconds. LED 1 will flash three times indicating end of programming.
7. Test the interface for proper functionality. Whenever a SWC is pressed LED 1 will illuminate green.
8. If any function does not work, repeat the programming steps.

Optional Programming Order

* Dual / Axxera, Jensen, Rockford Fosgate ** Jensen ONLY *** XAV-AX100 / 200 Only

Please Note: On any entry with multiple commands, the commands shown are source dependent.

Testing and Verification

1. Turn the ignition on. LED 1 will illuminate red and the +12v accessory wire will turn on.
2. Turn on the radio and check chimes, volume, balance, and fader.
3. In vehicles equipped with Premium Bose (Y91 / UQA): If the overall volume is too low, use the adjustment dial on the side of the interface to set it to the desired level. The best way to do this is to turn the volume on the radio to 3/4 volume, then turn the adjustment dial on the GM1A-RST clockwise until some distortion is heard, then counter-clockwise a little.
4. Verify that all SWC buttons are functioning properly for both the aftermarket radio and OnStar. To adjust OnStar volume, press the OnStar button on the mirror then use the volume buttons on the SWC to adjust the level. When you hear a chime during this process it means you have reached the farthest minimum / maximum level.
5. Pressing the OnStar button on the rearview mirror will turn off the rear speakers and allow the OnStar audio to be heard in the two front speakers. The OnStar active LED will also turn on. When OnStar disconnects, the radio will un-mute or turn back on and the OnStar LED will turn off. Pressing the VR / OnStar button on the steering wheel will also activate OnStar.
6. Turn off vehicle and remove key. RAP will be active and keep the radio on for 10 minutes or until any door is opened.
7. The LED and radio will turn off when RAP turns off or until any door is opened.

SWC Re-calibration Procedure (Corvette Only)

Please Note: This is only necessary if after installation, the SWC are acting erratic or unresponsive in the Corvette.

1. Turn the key to the ignition position.
2. Press and hold the programming button until LED 1 turns amber and you hear two chimes. When this happens, release the programming button.
3. Within 7 seconds, press and hold the button that is to be learned on the steering wheel. The LED will turn off when the button is pressed and begin blinking when the value has been learned. Once the LED begins blinking, release the button.
4. Repeat step 3 for each additional function on the steering wheel.
5. If you come to a button in the list that your vehicle does not have, skip it by pressing the programming button on the interface. Any buttons not learned during this process will not function.
6. Once programming is completed, the LED will flash indicating end of programming.
7. Test the interface for proper functionality. Whenever a SWC is pressed LED 1 on the interface should blink green. If any function does not work, repeat the programming steps.

Button Programming Order

• Volume Up
• Volume Down
• Seek Up
• Seek Down
• Preset
• Answer / Voice
• Hang Up
• Preset Up

Rear Seat Entertainment (RSE); If equipped

The factory RSE system will function independently from the aftermarket radio. The unit will power up and pass audio through the headphones as long as the vehicle's ignition is on. If you wish to pass audio from the RSE to the aftermarket radio you must connect the RCAs from the 12-pin connector to the aftermarket radios auxiliary input. Select the aftermarket radios auxiliary input to hear RSE audio.

RadioPRO PC App

Download the RadioPRO PC App at: https://aampglobal.com/radioproapp

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

• Configure User Interface Options such as:
  • Factory amplifier settings (Bass, Mid, Treble, Gain, Fader and Balance)
  • Chime Volume
  • Camera Settings
  • Telematics Volume
• 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

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

• Interface User Options
• Camera Settings
• Firmware Updates
• Reading firmware/hardware versions

RadioPRO PC App Adjustments

The RadioPRO PC app allows adjustments for Infotainment/Factory Amplifier settings (Y91 Premium systems only), including Amp Gain, Fader, Balance, Bass, Mid, Treble, and real-time fade. When real-time fade is enabled, fading is controlled directly from the aftermarket radio. Restoring factory settings defaults all values to the middle.

Telematics Volume can be adjusted via the RadioPRO PC app. Press the blue button on the mirror or the VR SWC to launch OnStar, then adjust the volume using the slider.

Chime Volume can also be adjusted through the RadioPRO PC app (not available in Premium Bose (Y91 / UQA) systems).

The app interface displays sections for configuring settings like Camera Settings, Interface User Options, Infotainment, Telematics, and Chime Volume. It also shows firmware update status and general information.

Firmware Updates

The RadioPRO PC app allows updating the interface with new firmware as it becomes available. Visit www.pac-audio.com/firmware for updates. Connect the interface to your PC, select "Firmware", then "Update Firmware". Select "Select File", browse to the saved file, and select it to begin the update. Once finished, disconnect the interface and test operation.

Technical Support

Email: support@PAC-audio.com

Phone: 866-931-8021

International: 727-572-9255 ext 230