HERMES Control Unit, Component Description - GF82.85-P-0221LF

Model 217, 222 with code 360 (HERMES UMTS)

Model 217, 222 with code 362 (HERMES communications module LTE)

Shown on model 222

Fig 1: HERMES Control Unit Component Location - Model 217 With Code 360 Or 362 (Shown On Model 222)

Courtesy of MERCEDES-BENZ USA

Location

The HERMES control unit is located behind the rear panel in the trunk on the control unit plate.

Tasks

The HERMES control unit is responsible for the following tasks:

Prioritization of the services in the internal arithmetic unit
Self-diagnosis, secures operational readiness of emergency call system by checking the following facts:
- Receipt of cyclic readiness signal ("Sign of life") from the supplemental restraint system control unit (N2/10)
- Connection for muting audio sources (mute function)
- Connection to driver hands-free system microphone (B25/20) (from model year 2018) or to hands-free system microphone (A67b1) (up to model year 2018) via the audio equipment
- Antenna connection as of model year 2018: Connection to the multifunction antenna (A28/11) (on model 222) or to the telematics services antenna (A2/49a1) and as of 01.06.2019 to the GPS antenna (A2/49a2) (on model 217)
  Additional connection to the left emergency call system antenna (A2/54), right emergency call system antenna (A2/55) (except code 360 (HERMES UMTS)), on vehicles with code 362 (HERMES LTE) via the telephone antenna splitter (A2/109) (on model 222) or the emergency call system antenna splitter (on model 217) (Sending and receiving diversity)
- Antenna connection up to model year 2018: Connection to the multifunction antenna (for model 222) or to the telematics services antenna (for model 217)
  Additional connection with code 362 (HERMES LTE) via the emergency call system antenna splitter (A2/25) to left emergency call system antenna and to right emergency call system antenna (sending and receiving diversity)
Reception of crash signals via the seat occupancy LIN (LIN E2) from Supplemental Restraint System control unit as trigger signal for the automatic emergency call (input)
Reception of GPS signals (Global navigation system) via the multifunction antenna (model 222 as of 01.06.2019) or via the GPS antenna (model 217 as of 01.06.2019)
Forwarding GPS signals to the head unit (as of 01.06.2019)
Establishing a voice or data link to the service provider via the antenna connection (input and output)
For voice connections: Sending of a muting signal (mute function) to the sound system amplifier control unit (N40/3) (with code 810 (Sound-System), up to model year 2018 also with code 811 (Advanced Sound-System)), to the Advanced Sound System amplifier control unit (as of model year 2018 with code 811 (Advanced Sound-System)) or to the audio equipment (except code 810 (Sound-System) and except code 811 (Advanced Sound-System)) (output)
For voice connections: Reception of signals from the driver hands-free system microphone (from model year 2018), hands-free system microphone by the audio equipment (input)
For voice connections: Sending of audio signals to the center instrument panel speaker (H4/27) (except code 811 (Advanced sound system)) or to the center instrument panel midrange speaker (H4/78) (with code 811 (Advanced sound system))
Power supply over circuit 30 and circuit 31 (input)
Forwarding real-time traffic data from the service provider via the WLAN antenna (A2/83) to the audio equipment
As of model year 2018: Position data from the head unit (A26/17), for the traffic data service, via the WLAN antenna (Input)
Up to model year 2018: Position data from the COMAND controller unit (A40/3) for traffic data service, with code 362 (HERMES LTE) via the WLAN antenna (Input)
Up to model year 2018: Position data from the COMAND controller unit for the traffic data service, with code 360 (HERMES UMTS) via a USB line (Input)
Communication of the Internet signals via a wireless connection over the W-LAN antenna to the audio equipment (up to model year 2018 with code 494 (USA version), from model year 2018) (radio interface)
CAN communication over diagnostic CAN (CAN D) with electronic ignition lock control unit (N73) (CAN interface)

The HERMES control unit can receive e.g. the following CAN signals from the electronic ignition lock control unit via the diagnostics CAN:

Circuit 15 status as trigger signal for self-diagnosis of emergency call system
Cyclic readiness signal ("sign of life") from the supplemental restraint system control unit as check signal
Crash information from the Supplemental Restraint System control unit (redundant), including crash level
Request to trigger automatic emergency call from Mercedes-Benz Intelligent Drive control unit (N62/4) (with code 23P (Driving Assistance package)), if the Active Emergency Stop Assistance brings the vehicle to a standstill.
Position data from the head unit (as of model year 2018) or from the COMAND controller unit (up to model year 2018), for position finding
Control signal of the SOS button (N70s11) (model 217.3, model 222) (manual emergency call)
Control signal of the SOS button (S93/3s2) (model 217.4) (manual emergency call)
Operation signal of Mercedes me connect button (N70s16) (model 217.3, model 222 as of 01.06.2018)
Operation signal of Mercedes me connect button (S93/3s6) (model 217.4 as of 01.06.2018)
Operation signal of MB Info button (N70s13) and the breakdown assistance button (N70s12) (model 217.3, model 222 up to 31.05.2018)
Operation signal of the MB Info button (S93/3s1) and the breakdown assistance button (S93/3s3) (model 217.4 up to 31.05.2018)
Operation signals of the button groups at the multifunction steering wheel (e.g. volume adjustment, mute function, create or disconnect connection)

The HERMES control unit can transmit the following CAN signals via diagnostic CAN, e.g.:

Test signal for self-diagnosis of emergency call system
Map data and miscellaneous data sent from the service center ("Remote Information Feed") via the electronic ignition lock control unit to the audio equipment
Status signals to the instrument cluster, over the electronic ignition lock control unit
Display messages for showing on the Audio/COMAND display (A40/8), via the electronic ignition lock control unit and the audio equipment

"HERMES" stands for: "Hardware for Enhanced Remote, Mobility & Emergency Services".

Structure

Internet-capable communications module:
- Cellular telephone system transceiver, which enables voice and data communication with the Service Center over the mobile phone frequencies.
- Ready for reception and transmission for 30 days: As soon as an SMS is received, the HERMES control unit is also activated (wake-up); after 30 days, the emergency call system goes into "sleep mode".
Bluetooth® interface
Radio interface for wireless local area network (WLAN)
Position finding module
GPS receiver for position finding (date, time, history and last-known location) for the listed vehicle-related services
Memory for vehicle-specific data
Buffer for navigation and other data that is transmitted to the vehicle

	Wiring diagram of HERMES control unit	N112/9 from model year 2018	PE82.85-P-2107-97SEB
		N1129 up to model year 2018	PE82.85-P-2107-97SEA