(Sound Generator Control Unit, Component Description - GF82.27-S-0010B)
Model 447
with code M7E (Electric motor 150 kW/battery 60 kWh (usable))
with code M8E (Electric motor 85 kW/battery 60 kWh (usable))
with code ME4 (Electric motor 145 kW)
with code XM7 (MOPF II)
The numbers on the pins indicate the pin numbering of the slots.
Overview
This document contains information on:
- General
- Function requirements
- Function
- Task
- Networking
- Ground connection
- Voltage supply
General
The sound generator control unit (N12/2) is installed in the footwell of the vehicle on the A-pillar on the left side of the vehicle
Function requirements
- Circuit 15ON
- Drive system "READY"
- Vehicle rolling.
Function
Task
The sound generator control unit (N12/2) emits an engine noise through the following speakers:
- Front sound generator speaker (H4/143)
- Rear sound generator speaker (H4/144)
The sound generator control unit (N12/2) is active at each start of operation up to a vehicle speed of 30 km/h and then switches itself off automatically. It is not possible to change the settings with regard to sound, volume, or switching on/off.
From 30 km/h onwards, the rolling noise of the tires and the vehicle's wind noise can be heard and, consequently, the need to generate artificial noise from the sound generator control unit (N12/2) is no longer necessary. The sound generator control unit (N12/2) is connected to the hybrid CAN (CAN L).
The Electronic Stability Program control unit (ESP®) (N30/4) uses the signals from the rotational speed sensors to calculate the vehicle speed and sends the calculated vehicle speed over the suspension FlexRay (Flex E) to the drivetrain control unit (N127).
Depending on the speed and the accelerator pedal position, a noise similar to the engine noise of a combustion vehicle is output between 0 and 30 km/h through the sound generator control unit (N12/2).
Networking
The sound generator control unit (N12/2) has both connections over direct lines as well as over the hybrid CAN (CAN L).
The following input and initial parameters are read in or output over direct lines by the sound generator control unit (N12/2):
| Input parameters over a direct line | Initial parameters over a direct line |
|---|---|
| Terminal 15 | - |
| Terminal 31 | - |
| - | Audio signal, positive |
| - | Audio signal, negative |
Input parameters and initial parameters for the following control units are sent or received by the sound generator control unit (N12/2) over the hybrid CAN (CAN L):
| Input parameters and output parameters over the hybrid CAN (CAN L) | Supplemental information |
|---|---|
| Head unit (A26/17) | - |
| High-voltage battery (G1/29) | - |
| DC current charge-connection unit (N24/6) | - |
| DC/DC converter control unit (N83/3) | - |
| Alternating current charger for high-voltage battery (N83/11) | - |
| HERMES control unit (N112/9) | - |
| Powertrain control unit (N127) | - |
To implement the function, the drivetrain control unit (N127) sends the following signals over the hybrid CAN (CAN L) to the sound generator control unit (N12/2):
- Current selector lever position
- Vehicle speed
- Pedal value
Ground connection
The "circuit 31" ground connection is then made
- on left-hand drive vehicles (code L) over a ground line to the left vehicle interior firewall ground point (W43/1).
- on right-hand drive vehicles (code R) over a ground line to the right vehicle interior firewall ground point (W43/2).
Voltage supply
When the ignition is "ON" the sound generator control unitN12 (/2) is powered by "circuit 15".