Amplifier Integration Interface for Select Ford vehicles with 8.4” Radio and Factory Sony Amplified System

$379.00 AP4-FD21
AmpPRO 4  Amplifier Integration Interface
  • This product is compatible with data-bus controlled amplified systems only. To identify these systems, look for logos on door speakers, tweeters, dash speakers or the subwoofer to confirm that the vehicle has a compatible amplified system. If you are unsure of your vehicle having an amplified system please contact an authorized Ford service center for further clarification.
  • 2018-2019 Super Duty Trucks can have either Sony or B&O systems to be compatible.
  • 2019+ Mustang must have B&O System to be compatible. If the amp looks like the one pictured, it is compatible. The amp can be found in the driver's kick panel. If the system is amplified and not badged then the AP4 is not compatible as this is a completely analog system. 


Amplifier Integration Interface for Select Ford vehicles with 8.4” Radio and Factory Sony Amplified System

Installation Instructions

  • Download the latest version of the AmpPRO PC Application. It is VERY important that you use the latest version.
  • Download the latest version of our firmware.
  • Extract the firmware file and setup file from the .ZIP files that were just downloaded.
  • Connect the interface to the computer's USB port and install the update.

Detailed Instructions

  1. If this is the first time using the AmpPROPC Application, run and install “ampproexe”. This will install the PC Application onto the computer. The AmpPRO program will then install the update files from the computer to the interface.
  2. Open the AmpPROPC Application using the new shortcut created on your desktop.
  3. Connect the interface to the computer using a standard to micro USB
  4. Click the "Firmware" icon.
  5. Click “Select File” and browse to the new firmware file. The new firmware can be found where you saved it before beginning.
  6. Once the file is chosen the update will begin. When successful it will show the text "Update Completed".
  • Firmware Download, Version (Released on January 20th, 2021)
    Release Notes

    ***No download available, hardware update only***

    • Minor hardware change. Does not affect user functionality
  • Firmware Download, Version V14 (Released on August 11th, 2017)
    Release Notes
    • Adds “Two Channel Mode” on Dip1
    • Reduces audio delay from ~14ms to ~1ms
  • Firmware Download, Version V11 (Released on March 16th, 2017)
    Release Notes
    • Fixes issue with Rear Cross Path Detection Chime not working
  • Firmware Download, Version V9 (Released on January 27th, 2017)
    Release Notes
    • Initial Release
  • Utility/Other, Version V17 (Released on July 31st, 2023)
    Release Notes
    AmpPRO PC Application
  • Utility/Other, Version 1 (Released on February 18th, 2021)
    Release Notes
    • Can be used for AP4 troubleshooting or for aftermarket amplifier gain setup
    • Contains the following test tones, all at 0dB
      • 20 Hz
      • 40 Hz
      • 100 Hz
      • 250 Hz
      • 350 Hz
      • 500 Hz
      • 1 kHz
      • 8 kHz

AmpPRO simplifies the installation of upgraded amplifiers in data-bus controlled amplified sound systems. With AmpPRO, you can improve audio performance while keeping an original radio’s fit, finish and features.


  • Simplifies amplifier installation
  • Prevents need for summing and DSP devices
  • Provides factory sound system upgrade solution
  • Can be used to upgrade the entire sound system or just part of it thanks to retention of original amplifier
  • Enables the addition of a subwoofer system to the original sound system
  • Variable volume, fade, balance, bass, mid and treble audio settings
  • Front, rear, sub preamp outputs (5 volt RMS)
  • Provides flat audio output for a solid audio foundation
  • Customized OE bass, mid and treble center frequency selection
  • Retains Sync, Bluetooth audio and all warning chimes
  • Plug & play installation
  • Sub level controller
  • Optional TOSLINK optical output (APA-TOS1 sold separately)

AmpPRO module
24-pin and 54-pin harness (MS CAN) (Dual MS CAN)
Bass knob
Knob harness

Also available for fast easy install: APH-FD01 harness (sold separately)

How it works:

AP4-FD21 Instruction Manual
Rev. 070617 ***Only applicable to revision firmware on AP4-FD21***
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AP4-FD21 Instruction Manual
Rev. 0530717 ***Only applicable to revision or lower firmware on AP4-FD21***
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