Engine Sound Control Unit, Component Description - GF54.21-P-0019FG

Model 213 with engine 177 up to model year 2019 except code 810 (Premium sound system) except code 811 (High-End sound system) except code B63 (Engine sound via speakers)

Model 213 with engine 256 up to model year 2019 except code 810 (Premium sound system) except code 811 (High-End sound system) except code B63 (Engine sound via speakers)

Model 213 with engine 276.823 up to model year 2019 except code 810 (Premium sound system) except code 811 (High-End sound system) except code B63 (Engine sound via speakers)

Model 213 with code B63 (Engine sound via speakers) except code 810 (Premium sound system) except code 811 (High-End sound system)

Illustration shows model 213

Fig 1: Engine Sound Control Unit Component Location - Model 213 With Engine 177, 256 Or 276.823 Up To Model Year 2019 Except Code(s) 810, 811 & B63

Courtesy of MERCEDES-BENZ USA

Location

The engine sound control unit is located at the rear left above the wheel arch.

Task

The engine sound control unit simulates the sound of the engine and exhaust system, which in the original cannot be fully heard in the vehicle interior. The simulated sound is output via the speaker system, even when no audio source is active.

For this purpose, the engine sound control unit implements the following tasks:

Reading in of sensors and signals
Evaluation of input factors
Actuation of components

Reading in of sensors and signals

The engine sound control unit reads in the input factors via the following connections:

Direct lines
Telematics CAN (CAN A)
Drive train CAN (CAN C1)

Direct lines

The engine sound control unit reads in control signals for the speaker system from the head unit (A26/17) via direct lines.

Telematics CAN

The engine sound control unit also reads in information on the tone setting from the head unit over the telematics CAN.

Drive train CAN

The engine sound control unit reads in the following signals via the drive train CAN:

Terminal status of terminal 15
On-board electrical system status
Transmission mode selection (transmission 725)
Engaged gear range (transmission 725)
Vehicle speed
Engine running status
Engine speed
Engine torque

Evaluation of input factors

The input factors that are read in are evaluated by the integrated microprocessor, and the audio signals are output.

Actuation of components

The engine sound control unit actuates the following component parts over direct lines:

Left front door midrange speaker (H4/1)
Right front door midrange speaker (H4/2)
Left rear door midrange speaker (H4/3)
Right rear door midrange speaker (H4/4)
Left front door tweeter (H4/33)
Right front door tweeter (H4/34)
Left front footwell woofer (right-hand drive vehicles) (H4/42)
Right front footwell woofer (left-hand drive vehicles) (H4/43)

Wiring diagram of engine sound control unit

PE54.21-P-2148-97DBA