To Next PageTo Next Page
Need help?Do you have a question about the Axxess GMOS-09 and is the answer not in the manual?
Lists specific Oldsmobile and Pontiac vehicles supported by the interface.
Details the wiring connections required from the 16-pin harness.
Details the wiring connections required from the 32-pin harness.
Steps for physically installing the GMOS-09 interface into the vehicle.
Procedures to verify the correct operation of the installed interface.
How to set the volume level for audible chimes.
How to adjust the audio output level of the aftermarket radio.
How to set the volume for OnStar communication.
The Axxess GMOS-09 is an installation interface designed for GM amplified OnStar Class II Data Bus vehicles manufactured between 2000 and 2004. This device facilitates the integration of an aftermarket radio into compatible vehicles, while retaining several key factory features. It is suitable for use in Oldsmobile Aurora models from 2001-2003 and Pontiac Bonneville models from 2000-2004, and can also be used in these vehicles even if they are not equipped with OnStar.
The primary function of the GMOS-09 is to provide a 12-volt, 10-amp accessory output, which is essential for the proper operation of an aftermarket radio. This ensures that the new radio receives power only when the vehicle's ignition is on, preventing battery drain. A significant convenience feature of this interface is its ability to retain Retained Accessory Power (R.A.P.). This means that the aftermarket radio, like the factory radio, will continue to operate for a short period after the ignition is turned off, until a door is opened, mimicking the original vehicle's behavior.
For vehicles with factory amplified systems, the GMOS-09 is specifically designed to work seamlessly, ensuring that the aftermarket radio's audio output is properly routed through the existing amplifier. This eliminates the need for complex rewiring of the vehicle's audio system. Another crucial retention feature is the vehicle's factory chimes. These chimes, which often signal important events like open doors, seatbelt warnings, or low fuel, will continue to function through the vehicle's speakers, maintaining critical safety and convenience alerts. The volume of these chimes is adjustable, allowing the user to set them to a comfortable level.
The GMOS-09 also offers valuable navigation outputs, which are particularly useful when installing an aftermarket navigation radio. These outputs include signals for the parking brake, reverse gear, mute function, and Vehicle Speed Sense (V.S.S.). The parking brake signal is often required by navigation units to enable certain features, such as address entry, while the vehicle is stationary. The reverse signal can be used to automatically display a backup camera feed when the vehicle is put into reverse. The mute output allows the navigation unit to temporarily silence the audio from the aftermarket radio for navigation prompts, and the V.S.S. signal provides accurate speed data to the navigation system, improving its positioning accuracy.
An ASWC (Axxess Steering Wheel Control) harness is included with the GMOS-09, although the ASWC module itself is sold separately. This harness simplifies the integration of steering wheel controls, allowing users to retain the functionality of their factory steering wheel buttons with their new aftermarket radio. This means that controls for volume, track skipping, and source selection can continue to be used from the steering wheel, enhancing driving convenience and safety.
For vehicles equipped with OnStar or factory Bluetooth, the GMOS-09 ensures that these features are retained. OnStar functionality, including emergency services and turn-by-turn navigation, will continue to operate as intended, with audio routed through the vehicle's front speakers. Similarly, if the vehicle has factory Bluetooth for hands-free calling, this feature will remain active. The volume for both OnStar and OE Bluetooth is adjustable, allowing for personalized audio levels.
The interface also incorporates a high-level speaker input, which can be useful in certain installation scenarios. This allows the GMOS-09 to accept speaker-level signals from an aftermarket radio, converting them to a format compatible with the vehicle's factory amplifier. The device is USB updatable, meaning that its firmware can be updated via a USB connection. This feature ensures that the GMOS-09 can be kept current with any future software improvements or compatibility updates, extending its lifespan and adaptability.
Maintaining the factory audio experience, the GMOS-09 retains both balance and fade controls. This allows users to adjust the audio distribution between the left and right speakers (balance) and the front and rear speakers (fade) from their aftermarket radio, just as they would with the factory unit.
Installation of the GMOS-09 involves connecting a 16-pin harness and an 18-pin harness (which connects to a 32-pin GM harness) to the aftermarket radio and the vehicle's wiring. The 16-pin harness includes wires for ignition, illumination, front and rear positive and negative speaker outputs, amplifier turn-on, mute, parking brake, VSS, and reverse. The 32-pin harness includes connections for battery power and ground. A specific Black/Yellow wire on the 16-pin harness is dedicated to OnStar volume adjustment.
The installation process begins with connecting the various wires from the 16-pin harness to their corresponding inputs on the aftermarket radio. For instance, the Red wire connects to the radio's ignition wire, the Orange/White wire to illumination, and the White and White/Black wires to the left front positive and negative speaker outputs, respectively. Similar connections are made for the right front, left rear, and right rear speakers. The Blue/White wire connects to the radio's amp turn-on, and the Brown wire to the radio's mute input. For navigation radios, the Light Green, Blue/Pink, and Green/Purple wires connect to the parking brake, VSS, and reverse inputs, respectively. Once these connections are made, the 16-pin harness plugs into the GMOS-09.
From the 32-pin harness, the Yellow wire connects to the radio's 12-volt battery or memory wire, and the Black wire connects to the radio's ground wire. The 14-pin harness then plugs into the GMOS-09. After all connections to the aftermarket radio are complete, the 24- and 12-pin harnesses are plugged into the vehicle's wiring harnesses.
Before reconnecting the negative battery terminal, it is crucial to ensure all accessories, switches, and especially air bag indicator lights are plugged in. This is a critical safety precaution recommended by Metra. Once reconnected, the key should be cycled by turning the ignition on for 30 seconds, then off and on again, to test the radio.
Testing the GMOS-09 involves several steps. First, with the ignition on, the radio should be turned on to verify its functionality, including balance and fader controls. Next, the OnStar button (if equipped) should be pressed to confirm OnStar operation. When OnStar is active, the radio will either shut off or mute (depending on whether the Brown mute wire is connected), and OnStar audio will be heard through the front speakers. Turning off OnStar should restore the radio's operation.
Maintenance features for the GMOS-09 primarily involve adjustments for chime, audio, and OnStar volume levels. The chime volume is adjusted using a potentiometer located on the 16-pin side of the interface. To adjust, with the car on, the ignition should be turned off, and the keys left in the ignition. Opening and leaving a car door open will activate the chimes. After a 10-second wait, a small screwdriver is used to adjust the potentiometer: counterclockwise to lower the chime level and clockwise to raise it. Once the desired volume is set, removing the keys from the ignition locks the chime volume.
Audio level adjustment is also done via a potentiometer. With the vehicle running and audio playing through the aftermarket radio, the radio's volume is set to about three-quarters of the way up. The potentiometer is then adjusted with a small screwdriver: clockwise to raise the audio level and counterclockwise to lower it, until the desired audio level is achieved.
OnStar volume adjustment is unique. It involves the Black/Yellow wire on the 16-pin harness. While the OnStar voice is speaking, the blue OnStar button is pressed, and the Black/Yellow wire is momentarily tapped to ground. There are four distinct volume settings for OnStar. Tapping the wire cycles through these settings, and after the fourth setting, it returns to the first. Once the desired volume is set, it remains at that level until the Black/Yellow wire is tapped to ground again. This adjustment can be made during installation and left alone, or if the vehicle has steering wheel controls, the customer may be able to adjust OnStar volume up or down using those controls.
The GMOS-09 is designed to be a robust and user-friendly solution for integrating aftermarket radios into specific GM vehicles, preserving essential factory features and enhancing the overall in-car entertainment experience.
General| Input Voltage | 12V DC |
|---|---|
| Output Voltage | 12V DC |
| Amplifier Turn-On | Yes |
| Navigation Outputs | Yes |
| Chime Retention | Yes |
| OnStar Retention | Yes |
