Hermes Control Unit, Component Description - GF82.85-P-0221FG
Model 213 up to model year 2021 with code 360 (HERMES UMTS)
Model 213 up to model year 2021 with code 362 (HERMES communications module LTE)
Shown on model 213.0 with code 360
(HERMES UMTS)
Shown on model 213.0 with code 362
(HERMES LTE) up to 31.05.2019
Location
The HERMES control unit is located under the center console near the head unit (A26/17).
Tasks
The HERMES control unit is responsible for the following tasks:
- Self-diagnosis for circuit 15 ON, secures operational readiness of emergency call system by checking the following facts:
- Reception of cyclic readiness signal from Supplemental Restraint System (SRS) control unit (N2/10)
- Connection for muting audio sources
- Connection to microphone for driver hands-free system (B25/20) through the head unit
- Connection to emergency call system antenna 1 (A2/140) or emergency call system antenna 2 (A2/141) (with code 362 (HERMES LTE))
- Reception of crash signals from the supplemental restraint system control unit (trigger signal for automatic emergency call)
- Establishing voice connections or data links to the service provider via the emergency call system antenna 1 or emergency call system antenna 2 (with code 362 (HERMES LTE))
- For voice connections:
- Transmission of a mute signal to the audio sources
- Reception of signals from microphone of driver hands-free system from head unit (input)
- Transmitting audio signals to the center instrument panel speaker (H4/27) (with standard equipment or with code 810 (Sound system)) or to the center instrument panel mid-range speaker (H4/78) (with code 811 (Advanced sound system))
- Reception of GPS (global navigation system) signals from the GPS antenna (A2/23) for position finding (as of 01.06.2019 or with code 506 (Audio 20 radio NTG 5.5), code 520 (Audio 20 USB), code 522 (Audio 20 radio) and except code 355 (Pre-installation for navigation retrofit))
- Forwarding of GPS signals to the head unit (as of 01.06.2019 with code 355 (Pre-installation for navigation retrofit) or with code 531 (COMMAND APS)) (output)
- Forwarding of real-time traffic data via the integrated radio interface and the WLAN antenna (A2/83) to the head unit and reception of position data from the head unit (with code 367 (Live Traffic Information) and code 506 (Audio 20 radio NTG 5.5) or code 531 (COMMAND APS))
- Forwarding of real-time traffic data via the multimedia connection unit (A90/5) to the head unit and reception of position data from the head unit (with code 367 (Live Traffic Information) and code 522 (Audio 20 radio))
- Communicating Internet signals to the head unit via WLAN (with code 506 (Audio 20 radio NTG 5.5) or code 531 (COMMAND APS)) or via Bluetooth® (with code 522 (Audio 20 radio) and code 494 (USA version))
- CAN communication via diagnostic CAN (CAN D)
- CAN communication through hybrid CAN (CAN L) (with code ME05 (HYBRID DRIVE 80KW VARIANT (INCLUDING PLUGIN)) or code ME06 (Hybrid drive 60 KW variant (Including plugin)))
The HERMES control unit receives, e.g. the following signals over the diagnostics CAN:
- Circuit 15 status from electronic ignition lock control unit (N73)
- Readiness signal from Supplemental Restraint System control unit
- Crash information from Supplemental Restraint System control unit (redundant)
- Request to trigger automatic emergency call from Mercedes-Benz Intelligent Drive control unit (N62/4) (with code 23P (Driving Assistance Package) or code P20 (Driving Assistance Plus Package)), if the Active Emergency Stop Assist brakes the vehicle until it comes to a standstill
- Status of SOS button (N70s11) from overhead control panel control unit (N70)
- Status of Mercedes me connect button (N70s16) (as of 01.06.018), status of breakdown assistance button (N70s12) (up to 31.05.2018) and status of MB-Info button (N70s13) (up to 31.05.2018) from overhead control panel control unit
- Control signals from controls on the multifunction steering wheel (e.g. volume control, mute, connect/disconnect)
- Steering wheel angle from the steering column tube module control unit (N80) for position finding
- Wheel speed signals, yaw rate signals from the Electronic Stability Program control unit (N30/4) for position finding
- Position data for position finding from the head unit (with code 355 (Pre-installation for navigation retrofit) or code 531 (COMMAND APS))
The HERMES control unit sends, e.g. the following signals over the diagnostics CAN:
- Check signal for the emergency call system self-test
- Map data and miscellaneous data transmitted by the Service Center ("Remote Information Feed") to the head unit
- Status signals to the instrument cluster
- Display messages to be shown on the Audio/COMMAND display (A40/8) to the head unit
On vehicles with code ME05 (HYBRID DRIVE 80KW VARIANT (INCLUDING PLUGIN)) or code ME06 (Hybrid drive 60 KW variant (including plugin)), the HERMES control unit communicates via the hybrid CAN with the powertrain control unit (N127) for the hybrid-specific telematics services, e.g. monitoring of charging processes and controlling auxiliary climate control.
HERMES stands for: Hardware for Enhanced Remote, Mobility & Emergency Services.
The HERMES control unit calculates the vehicle position and if necessary, it sends a message to the service center.
The HERMES control unit is prepared to send and receive for a period of 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".
Structure
The HERMES control unit contains the following components:
- Internet-compatible communication module with Bluetooth® interface and radio interface for 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 | PE82.85-P-2107-97DBA |