AP4-FD31
Introduction and Features
The AP4-FD31 provides a 6-channel pre-amp output for use with aftermarket audio equipment. Using the digital
A2B audio data in conjunction with CAN data, the AP4-FD31 delivers a variable 5v RMS pre-amp output with fading,
balance, equalization, and level control capabilities. The module also retains audio from other vehicle features such
as factory navigation prompts, safety chimes, Bluetooth and voice activation. A data bus controlled remote amplifier
turn on wire is also provided by the AP4-FD31. The module also provides a variable 2-channel fiber optic digital audio
output (TOSLINK).
Important Notes
1. This interface is only compatible in vehicles equipped with an A2B data bus controlled premium sound system. To verify
compatibility, look for a B&O badge on the door speakers or dash speakers.
2. The AP4 interface installs at the factory amplifier location. Included T-Harness installs behind radio to access factory
speaker wiring not available at factory amplifier.
3. The factory amplifier will be disconnected and will no longer power the vehicle speakers. An aftermarket amplifier must be
added to power the vehicle's speakers. For example, you cannot only add a subwoofer, as the factory speakers that were
connected to the factory amplifier will no longer function.
4. On most Ford models, some of the vehicle speakers will be connected to the radio module in addition to the external
amplifier. These speakers will also stop working when the factory amplifier is disconnected and will need to be powered by
an aftermarket amplifier. See Speaker Connections on Page 3 for vehicle specific speaker information.
5. The chime volume and minimum volume levels are set to 50% by default. If this level is adequate, no additional adjustment
is required. Please refer to the Setup and Configuration section on page 9 for more details.
6. The level control knob must be connected in order to manually adjust the chime volume and minimum volume settings.
7. The remote output is rated at 2A of current. If more current is needed, an external relay must be used.
8. Channels 5 and 6 are non-fading outputs. The output level of channels 5 and 6 can be controlled using the supplied level
control knob.
9. No adjustments can be made manually using the programming button, or the factory SWC, when the module is connected
to a PC.
Module Layout
Interface Connector 1
Expansion Port
Programming Button
USB Connection
Set DIP switches to the ON position to activate the corresponding features.
Set DIP switches to the OFF position for any features that are not desired.
Two Channel Mode
1 2 3 4
DIP
ON
Pacific Accessory Corporation
Feature Select
DIP switches
Non-Fading Level Control
Knob Connection
5v / 4v Preout
1
2
© 2021 AAMP Global. All rights reserved. PAC is a Power Brand of AAMP Global.
TOSLINK Output
Front Output
Ch. 1(L) and 2(R)
Rear Output
Ch. 3(L) and 4(R)
Not Used
3
PAC-audio.com
Advanced Amplifier Interface
for Select Ford Vehicles
LED 2
SUB (Non-Fading)
Ch. 5 and 6
Vehicle Select
4
Rev: 2
Date:020922
LED 1
Page 1