Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Functional description
Active Sound Design (ASD) is activated with terminal 30B ON.
The vehicle-specific and engine-specific algorithms for generating sound patterns are stored in the ASD control unit.
The central functionality of the ASD control unit is the synthesis of the ASD signals. The integrated digital sound processor generates an analogue signal. The generated signal is combined with the audio signal. Here, the ASD control unit functions as a sound generator. The ASD control unit varies this additional signal according to the relevant driving condition and pedal sensor position.
Via the CAN-Bus, the ASD control unit receives numerous parameters for the calculation of the ASD signals (e. g. engine speed, driving speed, pedal sensor position, load signal, engaged drive position).
| Item | Explanation |
|---|---|
| 1 | Active Sound Design (ASD) |
| 2 | 42 pin plug connection |
The following graphic shows the incorporation of the Active Sound Design (ASD) in the different audio systems.
- Stereo system
- Headunit ON and engine OFF:
Via the signal RAD_ON, the ASD control unit receives the information headunit ON. The audio signals are routed through the ASD control unit. In this audio system, the ASD control unit also functions as an audio amplifier.
- Engine ON and headunit OFF:
The ASD control unit outputs a generated signal via the speakers.
- Headunit ON and engine OFF:
- HiFi loudspeaker system (e. g. SA676)
- Headunit ON and engine OFF:
The hi-fi amplifier (AMPH) is activated via signal RAD_ON by the headunit (the signal is routed through the ASD control unit). The audio signals are routed through the ASD control unit.
- Engine ON and headunit OFF:
The hi-fi amplifier (AMPH) is activated via the signal RAD_ON by the ASD control unit.
- Headunit ON and engine OFF:
- HiFi system Professional (SA677) or Bang & Olufsen High End Surround Sound System (SA6F2)
- Headunit ON and engine OFF:
The Top HiFi amplifier (AMPT) or High End audio amplifier is activated via a signal on the MOST bus by the headunit.
- Engine ON and headunit OFF:
The Top HiFi amplifier (AMPT) or High End audio amplifier is activated via the signal RAD_ON by the ASD control unit.
- Headunit ON and engine OFF:
| Item | Explanation |
|---|---|
| 1 | Headunit |
| 2 | ASD control unit |
| 3 | Speakers |
| 4 | Hi-fi amplifier (AMPH) |
| 5 | Top HiFi amplifier or High End audio amplifier (AMPT) |
The following graphic shows the incorporation of the Active Sound Design (ASD) using the example of an acoustic sensor.
- Harman Kardon hi-fi loudspeaker system (e. g. SA674)
- Headunit ON and engine OFF:
The hi-fi amplifier (AMPH) is activated via signal RAD_ON by the headunit (the signal is routed through the ASD control unit). The audio signals are routed through the ASD control unit.
- Engine ON and headunit OFF:
The hi-fi amplifier (AMPH) is activated via the signal RAD_ON by the ASD control unit.
The ASD control unit outputs a generated signal via the speakers and the acoustic sensor.
- Headunit ON and engine OFF:
| Item | Explanation |
|---|---|
| 1 | Headunit |
| 2 | ASD control unit |
| 3 | Speakers |
| 4 | Hi-fi amplifier (AMPH) |
| 5 | Acoustic sensor |
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.