AXSUB-GM4 - Car audio interface Axxess - Free user manual and instructions

Product Type	Vehicle-specific subwoofer interface
Brand	AXESS
Model	AXSUB-GM4
Vehicle Compatibility	2019-up GM vehicles with RPO IOR, non-amplified models only
Dimensions (approx.)	3 x 2 x 1 in (76 x 51 x 25 mm)
Weight (approx.)	0.2 lb (90 g)
Power Supply	12V DC vehicle electrical system
Output Configuration	2-channel non-fading 5V RMS
Low Pass Filter	Fixed at 234 Hz
Remote Turn-On Output	250 mA
Main Functions	Adds aftermarket subwoofer to factory system; includes bass knob for level control
Installation Type	Plug-and-play with included T-harness; behind the radio
Included Components	AXSUB-GM4 interface, AXDSPX-GM4 T-harness (LD-DSP-GM31), bass knob (LD-BASSKNOB)
Firmware Update	Via Micro-B USB port
Safety	Disconnect battery negative terminal before installation
Maintenance	No maintenance required; keep dry and avoid moisture
Repairability	Not user-serviceable; contact technical support for issues
Spare Parts	T-harness and bass knob available separately; contact vendor
Certification	Meets applicable vehicle standards; MECP recommended installation

Frequently Asked Questions - AXSUB-GM4 Axxess

Which vehicles is the AXSUB-GM4 compatible with?

The AXSUB-GM4 is designed for 2019-up GM vehicles equipped with RPO IOR. It is only for non-amplified factory systems. Always check AxxessInterfaces.com for updated vehicle applications.

What is included in the box?

The package includes the AXSUB-GM4 interface, the AXDSPX-GM4 vehicle T-harness (LD-DSP-GM31), and the LD-BASSKNOB bass knob.

Do I need to bypass Active Noise Cancellation (ANC)?

Yes, if the vehicle has ANC microphones, they must be bypassed. Visit AxxessInterfaces.com for appropriate ANC bypass harnesses.

How do I program the interface after installation?

After connecting everything, turn on the ignition, set volume to minimum, and ensure the bass knob is fully left. Increase volume to desired level and wait up to 15 seconds for the aftermarket amp to turn on. The interface is now programmed.

What if I don't get sound from the subwoofer?

Check that the factory radio volume is not muted or at zero. Verify the 8-pin connectors are fully seated. Also ensure the bass knob is not turned all the way down.

Can I adjust the low-pass crossover frequency?

No, the low-pass filter is fixed at 234 Hz. This is designed for most subwoofer setups.

What is the output voltage of the RCA jacks?

The interface provides a 2-channel, 5V RMS non-fading output for the aftermarket amplifier.

How do I update the firmware?

Connect the interface to a computer using a Micro-B USB cable and visit AxxessInterfaces.com for update instructions and files.

Why doesn't the aftermarket amp turn on?

Ensure the bass knob is not at minimum, and check the Orange and Black wires from the interface to the knob are properly connected. Also verify the T-harness is seated correctly at the radio.

Where can I get technical support?

Contact Metra's tech support at 67-1187 or email [e-mail]. Hours: Mon-Fri 9AM-7PM, Sat 10AM-5PM, Sun 10AM-4PM (EST).

USER MANUAL AXSUB-GM4 Axxess

Collection of electronic components including capacitors, inductors, and connectors (no visible text or symbols)

GM (Add a SUB) Interface

2019-UP

Visit AxxessInterfaces.com for more detailed information about the product and up-to-date vehicle specific applications

INTERFACE FEATURES

• Can be used in non-amplified models only
• Easy behind the radio installation with pre-wired harness
• Bass knob included for level control of subwoofer amp
• Micro-B USB updatable

INTERFACE COMPONENTS

• AXSUB-GM4 interface
• AXDSPX-GM4 vehicle T-harness (LD-DSP-GM31)
  • Bass knob (LD-BASSKNOB)

NOTE: SELECT VEHICLES EQUIPPED WITH RPO: IOR

TABLE OF CONTENTS

Connections....2

Programming....3

Testing....3

Specifications....3

Troubleshooting....4

TOOLS REQUIRED

• Crimping tool and connectors, or solder gun, solder, and heat shrink • Tape • Wire cutter
• Zip ties • Multimeter

If the vehicle is equipped with Active noise cancellation (ANC) microphones, they will need to be bypassed. Please refer to www.Axxessinterfaces.com for ANC bypass harnesses offered for select vehicles.

www.AxxessInterfaces.com

MetraOnline.com may be used to assist with dash assembly instructions. Simply enter your Year, Make, Model vehicle into the vehicle fit guide and look for the Dash Kit Installation Instructions.

www.MetraOnline.com

ATTENTION: With the key out of the ignition, disconnect the negative battery terminal before installing this product, insure that all installation connections, especially the air bag indicator lights, are plugged in before reconnecting the battery or cycling the ignition to test this product. NOTE: Refer also to the instructions included with the aftermarket radio.

CONNECTIONS

graph TD
    A["Factory Radio"] --> B["Factory Radio Harness"]
    B --> C["Interface"]
    C --> D["4-Pin"]
    D --> E["AXXESS"]
    E --> F["20-Pin"]
    F --> G["LD-BASSKNOB"]
    G --> H["LD-DSP-GM31"]
    H --> I["Brown - Remote Turn On"]
    I --> J["Sub OUT"]
    J --> K["AXXESS®"]
    K --> L["Sub OUT"]
    L --> M["RCA Jacks (sold separately)"]
    M --> N["Blue/White - Amp Turn-On Wire"]
    N --> O["NOTE: SELECT VEHICLES EQUIPPED WITH RPO: IOR"]
    style A fill:#f9f,stroke:#333
    style B fill:#ccf,stroke:#333
    style C fill:#cfc,stroke:#333
    style D fill:#fcc,stroke:#333
    style E fill:#cff,stroke:#333
    style F fill:#ffc,stroke:#333
    style G fill:#cfc,stroke:#333
    style H fill:#fcc,stroke:#333
    style I fill:#ffc,stroke:#333
    style J fill:#cfc,stroke:#333
    style K fill:#fcc,stroke:#333
    style L fill:#cfc,stroke:#333
    style M fill:#fcc,stroke:#333
    style N fill:#cfc,stroke:#333
    style O fill:#fcc,stroke:#333

PROGRAMMING

1. With everything plugged in Turn on ignition and make sure audio volume is turned all the way down. Also ensure that your LD-BASSKNOB is turned all the way to the left.
2. Increase audio volume to desired listening level
3. Wait for aftermarket amp to turn on (up to 15 seconds)
4. You are now programmed

TESTING

1. Turn on audio and increase volume to desired level
2. Rotate the LD-BASSKNOB to the right to increase SUB level. Turn to the left to decrease SUB level

NOTE: Lowering the bass or volume knob completely will deactivate the aftermarket amplifier. Similarly, muting the radio will also result in turning off the aftermarket amplifier.

SPECIFICATIONS

• 2 Channel non-fading 5V RMS output
• Fixed low pass frequency of 234Hz
• 250mA remote turn on output

AXSUB-GM4

INSTALLATION INSTRUCTIONS

TROUBLESHOOTING

1. Not getting sound from Factory radio's speakers.

A) Make sure Factory Volume isn't set to zero or a mute button has been pressed on radio.
B) Make sure 8pin male and female connectors are plugged in to each other.

1. Not getting 12v on the Amp on out to amp

A) Make sure LD-BASSKNOB isn't turned all the way down(to left)
B) Your Orange and Black wires are properly connected from AXSUB-INTERFACE to LD-BASSKNOB

1. Not getting 12v on the Amp on out to amp

A) Make sure the t-harness is seated properly at the radio and OE harness.
B) Make sure the RCA's are connected to aftermarket amplifier.

Having difficulties? We're here to help.

Contact our Tech Support line at:

67-1187

email at: [e-mail]

Tech Support Hours (Eastern Standard Time)

Monday - Friday: 9:00 AM - 7:00 PM

Saturday: 10:00 AM - 5:00 PM

Sunday: 10:00 AM - 4:00 PM

Metra recommends MECP certified technicians