RadioPRO 4 Radio Replacement Interface

Introduction & Features

The RP4.2-BM21 interface allows the replacement of a factory radio in select BMW vehicles. Using this interface will retain factory features such as: steering wheel controls (SWC), iDrive controls and warning chimes (including rear park assist and front collision detection). Use of this interface also allows you to program two radio functions to each SWC button by using short press long press dual command functionality. The RP4.2-BM21 also provides data bus driven outputs such as data driven accessory power, vehicle speed signal (VSS), illumination, reverse and parking brake.

Important Notes

1. The factory warning chimes are audible either through the factory door speaker or through a separate speaker in the upper dash. In the event disconnecting the radio results in the vehicle losing the chimes, there are two ways to retain them. The RP4.2-BM21 must either be connected to the vehicle's hands-free speaker in the driver side under dash (using the supplied harness) or connected to the supplied speaker. The speaker can then be routed and mounted where desired.
2. The RadioPRO App is located on the PAC website (www.pac-audio.com) in the product description section of the RP4.2-BM21. This app will allow you to configure the user interface options, update product firmware and read the current hardware and firmware versions of the RP4.2-BM21 module. See page 5 for more information about this app.

Wiring Connection Chart

Note: BMW's power management system causes the constant power wire behind the radio to drop out after the key has been removed for 30 mins. It may be necessary to run a new 12V constant wire from the battery to the aftermarket radio.

Module Layout

The module layout diagram illustrates the physical components of the interface. It shows the location of the Radio Select Dipswitches, a USB Port, a Chime Speaker Connector, a Programming Button, Interface Connector 1, an Expansion Port, Interface Connector 2, a Module Status LED, and a Programmable Output/USB Status LED.

Installation Steps

1. The radio select dipswitches on the side of the interface must be adjusted to the proper radio setting before plugging the interface into the vehicle.
2. Find a constant power source. BMW's power management system causes the constant power wire behind the radio to drop out after the key has been removed for 30 mins. This is OK for the module but not for the aftermarket radio. For convenience, a 16ft 16AWG constant power wire is included to run constant power from the battery to the aftermarket radio. The battery in BMW vehicles is normally located in the trunk area. Route this wire away from any moving parts that may pierce or cut the wire.
3. Installation of the chime speaker (if required). If the vehicle has the factory telematics system (Bluetooth), use the RP4.2-BM21-SPK-HAR to retain factory warning chimes using the factory speaker mounted in the driver's kick panel. Disconnect the factory 3-pin connector from the speaker and connect the 3-pin connector from the RP4.2-BM21-SPK-HAR. Connect the other side (2-pin connector) to the RP4.2-BM21. If the vehicle does not have the factory telematics system, use the included speaker to retain the factory warning chimes.
4. If the vehicle has the HVAC recirculation button on the steering wheel and you wish to retain it, the brown wire in the interface's connector 2 must be connected to constant +12V prior to connecting the module to the vehicle. The brown wire will come disconnected, defaulting that button to control the aftermarket radio, not the HVAC.
5. Make all connections as described in the connection chart on page 1. For vehicles without a factory amplifier: Cut the RCA ends off the speaker wires and connect the aftermarket radio's front and rear speaker wires to the vehicle connector. For vehicles with a factory amplifier: Connect the RCA cables from the vehicle connector to the aftermarket radio's front and rear pre-amp outputs.
6. Connect the SWC wire to the aftermarket radio (the aftermarket radio must support a wired remote input).
7. Once all connections are made, plug the interface into the vehicle.
8. If you wish to reassign functions to the SWC, utilize short press long press dual command functionality, or assign the programmable 12V output to an SWC button, follow the optional programming instructions on the next page.

Steering Wheel Controls

Default Steering Wheel Control Programming

The interface comes pre-programmed for all factory SWC functions and does not require programming unless you wish to re-assign functions, utilize short press long press dual command functionality, or assign the programmable 12V output to an SWC button. The SWC can always be restored to default settings by pressing and releasing the program button on the interface once and waiting 7 seconds for the LED to flash 3 times.

In addition, 5 of the steering wheel controls are mirrored to the iDrive controller. For instance, the "+" button on the steering wheel performs the same function as the "Up" button on the iDrive controller. Reassigning a mirrored steering wheel control button will also change the corresponding iDrive function. See below for a list of mirrored functions.

Mirrored Functions

Default SWC Button Assignments

iDrive Buttons

Optional Steering Wheel Control Programming

Optional SWC Programming Procedure

1. Turn the key to the ignition position.
2. Press and release the programming button on the side of the interface. The Status LED will turn green.
3. Within 7 seconds, press the button that is to be learned on the steering wheel. The LED 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. The LED will turn back on. B. For long press functionality: Hold the button until the LED starts blinking. Release the button and the LED will go back to solid.
4. If you need to program more buttons, 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. The LED will flash three times indicating the end of programming.
7. Test the interface for proper functionality. Whenever an SWC is pressed, the LED on the interface should blink. If any function does not work, repeat the programming steps.

Optional Programming Order

*Other: Advent, Boyo, Dual, Lightning Audio, Rockford Fosgate, & Visteon

Short Press Long Press Dual Command Functionality

This feature allows you to assign two aftermarket radio functions to each of the vehicle's SWC buttons. It can be used with as many of the buttons as the user likes, or none at all. When this functionality is implemented, quickly pressing and releasing an SWC button will initiate the short press command, while pressing and holding an SWC button for longer than two seconds will initiate the long press command. Please note that no long press commands are programmed by default. If you wish to assign dual command functionality to the SWC, please follow the programming steps on the next page.

Programmable 12v Output

The Red/White wire on the interface can be programmed via the RadioPRO app to provide a pulsed or latched 12V output, which can then be assigned to any of the vehicle's factory SWC buttons. When assigned, the factory SWC button will activate the pulsed or latched output to control external accessories. Please refer to page 5 for more details on how to use the app to set this feature.

Testing & Verification

1. Turn the ignition on. The LED on the interface will turn on and the +12V accessory wire will turn on.
2. Turn on the radio and check balance & fade. (Premium systems may not fade.)
3. Verify that all SWC are functioning properly. The LED will flash whenever an SWC button is pressed, even if a function is not assigned to the button.
4. Verify that the programmable 12V+ output is functioning as intended.
5. The LED and radio will turn off when the ignition is turned off.

Restoring Factory Settings

You can restore the interface to factory default settings by pressing and holding the programming button on the side of the module until the status LED starts blinking red. Once the LED starts blinking red, release the button. You must release the button while the LED is blinking red in order to perform the reset.

This reset will restore the following settings to their factory defaults:

• SWC Mapping
• Programmable 12V+ Output (Latched)
• Parking Brake Output Settings
• Factory Warning Chime Volume (High)

RadioPRO App

Use of the RadioPRO App

Use of the RadioPRO App in BMW allows you to do the following:

• Configure user interface options such as: Red/White wire output behavior, aftermarket radio parking brake sequencing, and adjust warning chime volume level.
• Update product firmware.
• Read firmware/hardware versions.
• Access product user manuals.

Programmable Red/White Wire

The Red/White wire can be programmed to do a pulsed or latched trigger that is controlled by a user-assigned steering wheel control button, or it can be set to provide an output when triggered by the vehicle's foot brake, door, or trunk. The module will need to be connected to the vehicle so that the App can see what options are available from the specific vehicle. Once connected, select User Interface Options then set the behavior of the Red/White wire using the dropdown menu. Available triggers depend on what information is available on the vehicle's data bus. Restoring factory settings on the module will default this wire's output back to a latched SWC trigger.

Trunk: This selection will provide a 12V+ output on the Red/White wire whenever the CAN-Bus is active and the trunk is opened.

Alpine: If you select the "Alpine" setting on the dropdown menu, the Red/White wire will then work in conjunction with the parking brake output to produce the necessary sequencing for settings menu access. This sequencing is based on the actual parking brake, meaning to produce this sequence you have to engage the parking brake in the vehicle. If you would like to manually do the necessary foot brake/parking brake sequencing for Alpine, select the "Foot Brake" setting (if available) and the Red/White wire will output a 12V+ signal whenever the CAN-Bus is active and the foot brake is pressed.

Door: This selection will provide a 12V+ output on the Red/White wire whenever the CAN-Bus is active and any door on the vehicle is opened.

Footbrake: This selection will provide a 12V+ output on the Red/White wire whenever the CAN-Bus is active and the foot brake is pressed.

Latched: This selection will provide a latched 12V+ output that can be tied to any of the vehicle's SWC. This means that when you press the assigned SWC, the Red/White wire will turn on and remain on until the assigned SWC is pressed again or the ignition is turned off.

Pulsed Output

This selection will provide a user-programmable timed 12V+ output that can be tied to any of the vehicle's SWC. This means that when you press the assigned SWC, the Red/White wire will pulse for the pre-programmed user time. The range for pulse time is 100 milliseconds - 25.5 seconds (0.1-25.5).

Pioneer Parking Brake

Turning this feature on will make the parking brake output produce the necessary sequencing for settings menu access. This sequencing is based on the actual parking brake, meaning to produce this sequence you have to engage the parking brake in the vehicle. If you would like to manually do the necessary parking brake sequencing for Pioneer, simply leave this feature off. Restoring factory settings on the module will default this setting back to off.

Chime Volume

Changing this feature will either raise or lower the volume of the warning chimes through the speaker. If changing from Normal to High, then the volume will get louder. If changing from High to Normal, then the level will get softer. Keep in mind that this volume level will affect the rear park assist chimes and the front collision detection.

Product Updates (Firmware)

The RadioPRO app will also allow you to update the interface with new firmware as it becomes available. Please visit www.pac-audio.com or contact our tech support department to see if there is a firmware update for your interface.