Speaker Output Function - GF82.62-P-4212FRA
Model 257.361, 290
up to model year 2021
Function requirements for speaker output, general
- Circuit 30t ON
- Transport mode not active
Speaker output, general
The speaker system is actuated by one of the following components:
- Midline sound system amplifier control unit (except code 810 (Sound system) and except code 811 (Advanced Sound System))
- Sound system amplifier control unit (with code 810 (Sound system))
- Advanced Sound System amplifier control unit (with CODE 811 (Advanced Sound System))
A distinction is made between the following procedures:
- Speaker output in vehicles with code 811 (Sound system)
- Speaker output in vehicles with CODE 810 (Sound system)
- Speaker output in vehicles except code 810 (Sound system) and except code 811 (Advanced Sound System)
- Active engine noise compensation (AMGK) (with code 97B (Engine noise reduction via speakers))
Model 257.361, 290
up to model year 2021
with code 362 (HERMES communications module LTE)
The speaker actuation by the HERMES control unit (N112/9) is described elsewhere.
Speaker output in vehicles with code 811 (Sound system)
The audio signals from the head unit or TV tuner control unit (with code 865 (TV tuner)) are routed via MOST to the Advanced Sound System amplifier control unit, where they are finally amplified and output via the speakers using direct lines.
The head unit sends different variables for audio playback via MOST to the Advanced Sound System amplifier control unit, such as volume and tone settings or signals for speed-dependent volume control (SDV [GAL]) including interference recording.
In vehicles with engine 256, the Advanced Sound System amplifier control unit receives control signals (e.g. engine speed, engine load and vehicle speed) over the drive CAN from the ME-SFI [ME] control unit, superimposes the derived synthesized sound signals on the signals from the audio source, and issues the composite signals through the speakers.
The Advanced Sound System amplifier control unit emits the audio signals at the following speakers:
- Left front footwell woofer
- Right front footwell woofer
- Left front door sound system tweeter
- Right front door sound system tweeter
- Left rear door sound system tweeter
- Right rear door sound system tweeter
- Left front door sound system woofer/midrange speaker
- Right front door sound system woofer/midrange speaker
- Center instrument panel tweeter
- Center instrument panel midrange speaker
- Left rear door sound system midrange speaker
- Right rear door sound system midrange speaker
- Left front door midrange speaker
- Right front door midrange speaker
- Left rear shelf surround sound system tweeter
- Left rear shelf surround sound system midrange speaker
- Right rear shelf surround sound system tweeter
- Right rear shelf surround sound system midrange speaker
- Left front center overhead control panel midrange speaker (3D sound)
- Right front center overhead control panel midrange speaker (3D sound)
- Left center rear center midrange speaker (3D sound)
- Right center rear center midrange speaker (3D sound)
- Center midrange speaker at left center (3D sound)
- Center midrange speaker at right center (3D sound)
The signals for the rear woofer are sent by the Advanced Sound System amplifier control unit to the rear woofer amplifier, which outputs the finally amplified signals via the speaker.
Speaker output in vehicles with CODE 810 (Sound system)
The audio signals from the head unit or TV tuner control unit (with code 865 (TV tuner)) are routed via MOST to the sound system amplifier control unit, where they are finally amplified and output through the speakers using direct lines.
The head unit sends different variables for audio playback over MOST to the sound system amplifier control unit such as, e.g. volume and tone settings and signals for speed-dependent volume control (SDV [GAL]) including interference recording.
In vehicles with engine 256, the sound system amplifier control unit receives control signals (e.g. engine speed, engine load and vehicle speed) over the drive CAN from the ME-SFI [ME] control unit, superimposes the derived synthesized sound signals on the signals from the audio source, and issues the composite signals through the speakers.
The sound system amplifier control unit emits the audio signals at the following speakers:
- Left front door midrange speaker
- Right front door midrange speaker
- Left rear door midrange speaker
- Right rear door midrange speaker
- Center instrument panel speaker
- Left front door tweeter
- Right front door tweeter
- Left rear door tweeter
- Right rear door tweeter
- Left front footwell woofer
- Right front footwell woofer
- Left rear surround sound system midrange speaker
- Right rear surround sound system midrange speaker
- Rear bass speaker (model 290)
Speaker output in vehicles except code 810 (Sound system) and except code 811 (Advanced Sound System)
The audio signals from the head unit or TV tuner control unit (with code 865 (TV tuner)) are routed over MOST to the Midline sound system amplifier control unit, where they are finally amplified and output through the speakers using direct lines.
The head unit sends different variables for audio playback over MOST to the Midline sound system amplifier control unit such as, e.g. volume and tone settings and signals for speed-dependent volume control (SDV [GAL]) including interference recording.
The Midline sound system amplifier control unit receives control signals (e.g. engine speed, engine load and vehicle speed) over the drive CAN from the ME-SFI [ME] control unit (gasoline engine), superimposes the derived synthesized sound signals on the signals from the audio source, and issues the composite signals through the speakers.
The Midline sound system amplifier control unit issues the audio signals at the following speakers:
- Left front door midrange speaker
- Right front door midrange speaker
- Left rear door midrange speaker
- Right rear door midrange speaker
- Center instrument panel speaker
- Left front door tweeter
- Right front door tweeter
- Left footwell woofer
- Right footwell woofer
Additional function requirements for active engine noise compensation (AMGK) (with code 97B (Engine noise reduction via speakers))
- Internal combustion engine running.
Active engine noise compensation (AMGK) (with code 97B (Engine noise reduction via speakers))
A cylinder shutoff during engine operation can generate low-frequency engine noise that may be perceived as unpleasant. The active engine noise compensation reduces this noise in the vehicle interior through the generation of antinoise through the speaker system.
To calculate the actuation of the speakers the sound system amplifier control unit (with code 810 (Sound system)) or the Advanced Sound System amplifier control unit (with code 811 (Advanced Sound System)) requires the engine speed from the ME-SFI [ME] control unit over the drive CAN and the microphone signals of the following microphones over a direct line:
- Left front active engine noise compensation microphone
- Right front active engine noise compensation microphone
- Left rear active engine noise compensation microphone
- Right rear active engine noise compensation microphone
Disturbing, low-frequency noise in the overall noise level of the vehicle interior are detected based on the engine speed and the microphone signals.
In vehicles with code 810 (Sound system) the following speakers are actuated by the sound system amplifier control unit to generate antinoise:
- Left footwell woofer
- Right footwell woofer
- Rear woofer
In vehicles with code 811 (Advanced Sound System), the following speakers are actuated by the Advanced Sound System amplifier control unit to generate antinoise:
- Left footwell woofer
- Right footwell woofer
- Left front door sound system woofer/midrange speaker
- Right front door sound system woofer/midrange speaker
- Rear bass speaker, over the rear bass speaker amplifier
| Electrical function schematic for speaker system | PE82.62-P-2300-97XBB | ||
| Overview of system components, telematics | GF82.85-P-9999FR |