Component Description For Sound System Amplifier Control Unit - GF82.62-P-5010FR

Model 257, 290 

up to model year 2021 

with code 810 (Premium sound system) 

except code 811 (High-End sound system) 

Shown on model 257.3 

Courtesy of MERCEDES-BENZ USA

Location 

The sound system amplifier control unit is located in the left of the trunk behind the side trim.

Tasks 

• Receive signals 
• Signal optimization and amplification 
• Transmitting signals 
• Active engine noise compensation (AMGK) (model 290 with code 97B (Engine noise reduction via speakers)) 

Receive signals 

The input factors are read in via:

• Direct lines 
• Media Oriented System Transport (MOST) 
• CAN (model 257 with code B63 (Sporty engine sound) or model 290 with engine 256 or model 290 with code 97B (Engine noise reduction via speakers)) 

Direct lines 

The following signals are read in via a direct line:

• Power supply via circuit 30t and circuit 31
• Audio muting (Mute function) from the HERMES control unit (N112/9) (with code 362 (HERMES LTE))
• Electrical wake-up
• Microphone signals (model 290 with code 97B (Engine noise reduction via speakers)) from the following components:
  • Left front active engine noise compensation microphone (B25/28)
  • Right front active engine noise compensation microphone (B25/29)
  • Left rear passenger compartment active engine noise compensation microphone (B25/30)
  • Right rear passenger compartment active engine noise compensation microphone (B25/31)

Media Oriented System Transport (MOST) 

The sound system amplifier control unit is a MOST subscriber and receives control and audio signals from the following components:

• Head unit (A26/17)
• TV tuner control unit (N143) (with code 865 (TV tuner))

CAN (model 257 with code B63 (Sporty engine sound) or model 290 with engine 256 or model 290 with code 97B (Engine noise reduction via speakers)) 

The sound system amplifier control unit receives control signals (e.g. engine speed, engine load and vehicle speed) over the drive train CAN (CAN C1) from the CDI control unit (N3/9) or from the ME-SFI [ME] control unit (N3/10)

Signal optimization and amplification 

The sound system amplifier control unit has the following tasks when it is optimizing and amplifying the signals:

• Optimize the input signals by digital signal processing and Surround Sound
• Support of stereo and multichannel entertainment channels and announcement channels (e.g. for voice output in voice control system or navigation prompts)
• Amplifying of the input signals and assignment of the output to the speakers
• Model 257 with code B63 (Sporty engine sound) or model 290 with engine 256: Optimization of engine and exhaust system sound in the vehicle interior by augmenting the sound panorama with simulated sound components

Transmitting signals 

The sound system amplifier control unit transmits signal tones and amplified, optimized audio signals to the following speakers via direct lines:

• Left front door midrange speaker (H4/1) and left front door tweeter (H4/33)
• Right front door midrange speaker (H4/2) and right front door tweeter (H4/34)
• Left rear door midrange speaker (H4/3) and left rear door tweeter (H4/35)
• Right rear door midrange speaker (H4/4) and right rear door tweeter (H4/36)
• Center instrument panel speaker (H4/27)
• Left front footwell bass speaker (H4/42)
• Right front footwell bass speaker (H4/43)
• Left rear midrange speaker for surround sound system (H4/62)
• Right rear midrange speaker for surround sound system (H4/63)
• Rear bass speaker (H4/38) (model 290)

Active engine noise compensation (AMGK) (model 290 with code 97B (Engine noise reduction via speakers)) 

When the engine is running, low-frequency engine noises may be produced at cylinder shutoff, which may be considered obtrusive. The sound system amplifier control unit detects the obtrusive noises on the basis of the engine speed and the microphone signals.

The sound system amplifier control unit reduces the obtrusive noises in the vehicle interior by generating counter-noise via the following speakers:

• Left front footwell woofer
• Right front footwell woofer
• Rear woofer

Sound amplifier control unit wiring diagram

PE82.62-P-2101-97XBA