P82.95-3174-79
Shown: model 207 |
A1 | Instrument cluster | N2/10 | Supplemental restraint system control unit | S111 | Right multifunction steering wheel button group | ||
A2 | Radio (with CODE 505 (Radio 20 NTG5 without navigation capability) or with CODE 522 (Audio 20 radio)) | N10/1 | Front SAM control unit with fuse and relay module | S111s1 | Buttons + and - for setting specific functions and volume control | ||
A2/52 | Emergency call system antenna | N30/4 | Electronic Stability Program control unit (except CODE 233 (DISTRONIC PLUS)) | S111s3 | Accept/terminate phone call button | ||
A2/83 | WLAN antenna (with CODE 531 (COMAND APS)) | N30/7 | Premium Electronic Stability Program control unit (with CODE 233 (DISTRONIC PLUS)) | CAN A | Telematics CAN | ||
A2/91 | Bluetooth antenna (with code 522 (Audio 20 radio)) | N40/3 | Sound system amplifier control unit (with CODE 810 (Sound system)) | CAN B | Interior CAN | ||
A28/11 | Multifunction antenna (with code 362 (HERMES LTE) and with code 494 (USA version)) | N49 | Steering angle sensor | CAN D | Diagnostic CAN | ||
A40/3 | COMAND controller unit (with CODE 531 (COMAND APS)) | N73 | Electronic ignition switch control unit | CAN E1 | Chassis CAN 1 | ||
A40/8 | Audio/COMAND display | N80 | Steering column module control unit | CAN E2 | Chassis CAN 2 | ||
A40/9 | Audio/COMAND control panel | N112/9 | HERMES control unit | LIN E1 | Steering LIN | ||
A67b1 | Hands-free system microphone | N135 | Steering wheel electronics | MOST | Media Oriented System Transport | ||
H4/27 | Center instrument panel speaker | S93/3 | Emergency call system button | LVDS | Low voltage differential signal |
Function requirements, emergency call system, general
Circuit 30
Transport mode is inactive.
The communications module of the HERMES control unit is configured with the telephone number of the relevant service provider.
Emergency call system, general
The emergency call system allows a manual or automatic emergency call to be triggered. The emergency call is received by the Mercedes-Benz Service Center. The user is spoken to in the language that is selected in the system settings of the audio equipment. If necessary, the Mercedes-Benz Service Center notifies the local rescue services. If the Mercedes-Benz Service Center is not staffed, the emergency call is automatically forwarded to the local rescue services 112.
If the HERMES control unit receives the message "Circuit 15" from the front SAM control unit with fuse and relay module via diagnostic CAN, it checks the operational readiness of the emergency call system. After a successful check, the emergency call system is operational and "SOS ready" appears on the Audio/COMAND display. The following checks are carried out:
Receipt of cyclic readiness signal ("sign of life") from the supplemental restraint system control unit
Connection for muting audio sources
Connection to hands-free system microphone, from audio equipment
Connection to emergency call system antenna
Connection to multifunction antenna (with code 362 (HERMES LTE) and with code 494 (USA version))
In the event of a fault, depending on the fault type, a fault message appears on the Audio/COMAND display and the fault code is stored in the fault memory of the HERMES control unit. If, after switching off the ignition, the Supplemental Restraint System control unit switches to the "Sleep" mode, it no longer sends a readiness signal and the "SOS NOT READY" message is shown.
The electronic ignition lock control unit sends the "Circuit 15" message over the following path:
Interior CAN
Front SAM control unit with fuse and relay module
Diagnostic CAN
HERMES control unit
The emergency call system function comprises the following subfunctions:
Emergency call system status indication
Position finding
Manual or automatic emergency call
Emergency call system status indication
The status of the emergency call system is shown in the following ways:
Status indication on the Audio/COMAND display
Status indication via light-emitting diode
Status indication in instrument cluster
Status indication on the Audio/COMAND display
The status of the emergency call system is indicated by a text message on the Audio/COMAND display in the following cases:
Emergency call system operational or not operational ("SOS ready" or "SOS not ready" in telephone menu)
Emergency call has been activated ("activating" (call setup), "transmitting data" (data telegram transmission), "connected" (voice connection established))
Emergency call forwarded to local 112 rescue services (the address (with code 531 (COMAND APS)) and the coordinates of the vehicle position are also shown)
Call activation has failed several times ("MB emergency call processing failed. Please dial 112 on the mobile phone.")
If an emergency call is active, the top right of the Audio/COMAND display also shows a telephone symbol, an emergency call symbol and the field strength of the HERMES control unit.
The HERMES control unit sends the display over the following path:
Diagnostic CAN
Front SAM control unit with fuse and relay module
Interior CAN
Audio equipment
LVDS line
Audio/COMAND display
Control communication (e.g. switch-on) is sent by the audio equipment over the telematics CAN to the Audio/COMAND display.
Some text messages on the Audio/COMAND display can be confirmed using the Audio/COMAND control panel. The Audio/COMAND control panel sends the signals via the following route:
Telematics CAN
Audio equipment
Interior CAN
Front SAM control unit with fuse and relay module
Diagnostic CAN
HERMES control unit
Status indication via light-emitting diode
The LED of the emergency call system button is used to indicate the following status:
Active service, light-emitting diode flashes.
Emergency call system self-diagnosis, light-emitting diodes light up for approx. 5 s.
Fault in emergency call system, LEDs permanently on.
Diagnosis
The HERMES control unit actuates the emergency call system button LED directly.
Status indication in instrument cluster
If the HERMES control unit fails, the instrument cluster shows "SOS nonfunctional". The failure of the HERMES control unit is reported over the following path:
Diagnostic CAN
Front SAM control unit with fuse and relay module
Interior CAN
Instrument cluster
Position finding
In vehicles with code 522 (Audio 20 radio) or with code 531 (COMAND APS) the HERMES control unit takes over the position finding signals from the audio equipment. The audio equipment sends the signals via a USB line (universal serial bus) to the HERMES control unit. On vehicles with code 494 (USA version), the audio equipment sends the signals via WLAN antenna (A2/83) (with code 531 (COMAND APS)) or the Bluetooth antenna (A2/91) (with code 522 (Audio 20 radio)) to the respective interface of the HERMES control unit.
In vehicles with code 505 (Radio 20 NTG5 non-navigation-capable) the position finding is conducted by the HERMES control unit. For position finding, the HERMES control unit uses the global navigation system (GPS). GPS is available worldwide. GPS position finding is irretrievable after vehicle transport (e.g. by train or ferry or after towing). Subsequent GPS position finding (following an interruption in satellite reception) can take several minutes. At the same time as the GPS position finding the HERMES control unit conducts a permanent basic position finding, that enables the position of the vehicle to be determined even when the GPS reception fails.
The position finding function consists of the following component functions:
GPS position finding
Basic position finding (with code 505 (Radio 20 NTG5 non-navigation-capable))
GPS position finding
In vehicles with code 522 (Audio 20 radio) or with code 531 (COMAND APS) the audio equipment receives the GPS signals from the multifunction antenna.
In vehicles with code 505 (Radio 20 NTG5 non-navigation capable), the HERMES control unit receives the GPS signals from the multifunction antenna.
Additional function requirements for basic position finding (with code 505 (Radio 20 NTG5 non-navigation-capable))
Circuit 15 ON
Basic position finding
The HERMES control unit requires the following signals for basic position finding:
Wheel speed and yaw rate signals from the Electronic Stability Program control unit (except CODE 233 (DISTRONIC PLUS)) or from the Premium Electronic Stability Program control unit (with CODE 233 (DISTRONIC PLUS))
Signal from the steering angle sensor
The Electronic Stability Program control unit (except code 233 (DISTRONIC PLUS)) or the Premium Electronic Stability Program control unit (with code 233 (DISTRONIC PLUS)) sends the wheel speed and yaw rate signals via the following route:
Chassis CAN 1
Front SAM control unit with fuse and relay module
Diagnostic CAN
HERMES control unit
The steering angle sensor sends the signal via the following route:
Steering column tube module control unit
Chassis CAN 1
Front SAM control unit with fuse and relay module
Diagnostic CAN
HERMES control unit
The HERMES control unit uses the data to calculate the instantaneous position of the vehicle (longitude, latitude and direction of travel).
Location errors in position finding, rolling backwards with "circuit 15 OFF" (ignition switched off) or transport of the vehicle falsify the basic position finding. In both cases, this deviation is automatically corrected on receipt of GPS data.
Manual or automatic emergency call
In an emergency situation, a service receptionist from the Mercedes-Benz Service Center can obtain an overview of the condition inside the vehicle with the aid of the data received from the HERMES control unit (voice connection and data telegram) and initiate appropriate help measures. An emergency call be initiated manually or automatically. These emergency calls are made for the following reasons:
Automatic alerting of the rescue services after an accident
Alerting rescue services by pushing a button (own emergency situation, observed accident)
Reduction in rescue times through fast emergency notification with details on exact location involved
The automatic emergency call has priority over a manually triggered emergency call. If an automatic emergency call is triggered during a manual emergency call, the manual emergency call is interrupted. If a manual emergency call is triggered during an automatic emergency call, it is ignored. However, a data telegram containing updated position data is sent to the Mercedes-Benz Service Center, and the existing connection is maintained.
The manual or automatic emergency call function consists of the following subfunctions:
Triggering of an automatic emergency call
Triggering of a manual emergency call
Voice connection between vehicle and Service Center
Additional function requirements for triggering an automatic emergency call
Circuit 15 ON
Triggering of an automatic emergency call
In the event of an accident with deployment of the restraint systems (not the PRE-SAFE® system) an automatic emergency call (eCall) is immediately sent. An emergency call is sent out regardless of the severity of the accident.
The HERMES control unit receives the crash information over a direct line as a digital crash signal from the supplemental restraint system control unit.
The supplemental restraint system control unit also (redundantly) sends the crash information, including crash level, via the following route:
Chassis CAN 1
Front SAM control unit with fuse and relay module
Diagnostic CAN
HERMES control unit
The supplemental restraint system control unit transmits a readiness signal cyclically via the same route (e.g. every 500 ms). This enables the HERMES control unit to monitor communication with the supplemental restraint system control unit and correct operation of the crash detection.
Additional function requirements for triggering a manual emergency call
No automatic emergency call is active.
Triggering of a manual emergency call
The manual emergency call is triggered by pressing the emergency call system button. The emergency call system button is covered up with a locking flap. Pressing the protective lid unlocks the lid, and it automatically opens with the aid of a spring mechanism.
The signals of the emergency call system button are sent directly to the HERMES control unit.
Voice connection between vehicle and Service Center
After triggering the emergency call, the HERMES control unit sets up a voice connection to the Mercedes-Benz Service Center via the emergency call system antenna or multifunction antenna (with code 362 (HERMES LTE)) and code 494 (USA version).
Model 207
as of model year 2017
with code 351 (eCall emergency call system)
with code 362 (HERMES communications module LTE)
except code 347 (Mercedes-Benz emergency call system)
except code 348 (Emergency call/assistant system)
The multifunction antenna and the emergency call system antenna are used to set up the connection to achieve transmission and reception diversity.
The status of the connection setup is indicated by the following messages on the Audio/COMAND display:
"Activating" (setting up the call)
"Transmitting data" (transmission of emergency call data (data telegram))
"Connected" (voice connection established)
The activation of a voice connection to the Mercedes-Benz Service Center is canceled after several failed attempts to connect, and the following message is shown on the Audio/COMAND display: "MB emergency call activation failed. Please dial 112 on the mobile phone."
During an automatic emergency call, the accept/terminate phone call button on the multifunction steering wheel is temporarily disabled while the connection is being set up in order to avoid unintentional termination.
While the connection is being set up, audio sources are muted (mute function) and existing telephone connections are interrupted.
In vehicles except code 810 (Sound system), the HERMES control unit sends the signal for the mute function to the audio equipment.
In vehicles with code 810 (Sound system), the HERMES control unit sends the signal for the mute function to the sound system amplifier control unit.
As soon as a connection is set up to the Mercedes-Benz Service Center, the HERMES control unit automatically sends a data telegram to the Service Center. The data telegram transmits the following data:
Time stamp
GPS position of vehicle
Language
Vehicle identification number
MB Contact status (ON or OFF)
Position history (Tracing of vehicle positions up to a distance of a few 100 m from current location)
Number of vehicle occupants (estimated)
After a data telegram has been transmitted to the Mercedes-Benz Service Center, the user can speak to a service receptionist via the voice connection. The Mercedes-Benz Service Center carries out the call, where possible, in the language that was selected in the system settings of the audio equipment and transmitted in the data telegram. The hands-free system microphone is used for the voice input. The hands-free system is not available for telephone calls throughout the duration of the emergency call.
The HERMES control unit receives the outgoing voice signals over the audio equipment via the hands-free system microphone.
The HERMES control unit outputs the incoming voice signals over the center instrument panel speaker.
The voice output volume can be adjusted using the + and - button, setting of specific functions and the volume control of the right multifunction steering wheel button group.
The Accept/terminate phone call button of the right multifunction steering wheel button group can be used to end the emergency call, if this is not done by the Mercedes-Benz Service Center.
The right multifunction steering wheel button group sends the control signals via the following route:
Steering wheel electronics
Steering LIN
Steering column tube module control unit
Chassis CAN 1
Front SAM control unit with fuse and relay module
Chassis CAN 2
Instrument cluster
Interior CAN
Front SAM control unit with fuse and relay module
Diagnostic CAN
HERMES control unit
With a manual or an automatic emergency call, the Service Center can transfer the map data to the vehicle if required. The data is made available to the navigation module of the audio equipment.