Telematic Communication Box
Telematic Communication Box
Telematic Communication Box (TCB)
The Telematic Communication Box (TCB) performs all Telematic functions in the vehicle. These functions include:
- Emergency-call function
- Online services
- BMW Remote Access Service
Information on online services and Remote Access Service can be found in the functional description BMW Telematics Professional.
Brief component description
The following components for the Telematic Communication Box (TCB) are described:
- Control unit for Telematic Communication Box (TCB)
- Aerials/antennas
- SOS button with emergency call LED
- Emergency loudspeaker
- Microphone
TCB: Control unit for Telematic Communication Box
The control unit for the Telematic Communication Box (TCB) is connected to the Controller Area Network bus. It comprises a metal base plate, as well as a plastic housing. A battery compartment is integrated on the top side, which includes the emergency battery (see section "Emergency battery").
Aerials/antennas
Up to 3 different aerials are required for the telematics function:
- GSM aerial integrated in roof aerial
- Emergency GSM aerial
- GPS aerial integrated in roof aerial (only if there is no navigation system)
Roof aerial
The housing of the roof-mounted aerial contains the following aerials:
- Telephone aerial (GSM 1) for mobile phone
(GSM stands for Global Standard for Mobile Communications)
- Telephone aerial (GSM 2) for telematics services
- GPS aerial (optional)
(GPS stands for Global Positioning System)
Within the scope of certain optional equipment, further additional aerials which are not for the telephone or telematics may be installed in the roof-mounted aerial (e. g. Digital Audio Broadcasting, Satellite Digital Audio Radio Service).
The following graphic shows the Roof aerial using the example of F01.
Emergency GSM aerial
The emergency GSM aerial is secured to the storage shelf (can vary depending on vehicle type).
If the restraint systems are activated, the Crash Safety Module sends a signal to the Telematic Communication Box (TCB). The control unit automatically initiates an emergency call, which also contains the location of the vehicle.
An aerial selector is integrated in the Telematic Communication Box (TCB). The aerial selector is used to switch over to the emergency GSM aerial if the GSM aerial in the roof-mounted aerial fails (e.g. due to an accident). Switch-over is carried out automatically if the GSM aerial in the roof-mounted aerial has poorer reception than the emergency GSM aerial.
If the vehicle is not fitted with a navigation system, the Telematic Communication Box (TCB) has its own GPS module and its own connection to the GPS aerial. If the vehicle is fitted with a navigation system, the Telematic Communication Box (TCB) is powered from the headunit with the position data.
During an emergency call, the data is transferred to a server and stored. The data can be used by the service provider for initiating the rescue measures.
SOS button with emergency call LED
The emergency call button with emergency call LED is connected directly to the Telematic Communication Box (TCB).
Triggering an emergency call:
- Touch the covering flap of the emergency call button and open it.
- Press the emergency call button until the emergency call LED lights up. The connection is established.
- When the emergency call LED flashes, the connection has been established.
The manual emergency call can be cancelled within 5 seconds.
The following graphic shows the emergency call button with emergency call LED in the roof function centre with the example F01.
Emergency loudspeaker
If an emergency call is made, the Service Provider endeavours to establish voice contact with the occupant. This voice contact enables the Service Provider to obtain further information about the accident (accident severity, number of people injured). This then enables the corresponding rescue measures to be initiated.
Whenever voice contact is established, the occupant is able to hear the Service Provider through the emergency loudspeaker. The microphone on the driver's side is always used for the hands-free mode during an emergency call.
During a manual or automatic emergency call the sound output always takes place over the emergency loudspeaker.
Emergency battery
The emergency battery will be installed from 03/2013.
The emergency battery is designed as a nickel metal hydride battery with 4.8 V and a capacity of 600 mAh. The emergency battery serves as a voltage source if the voltage supply of the vehicle for the Telematic Communication Box (TCB) is interrupted due to an accident for example. In this case, an emergency call can be placed and the connection to the emergency centre maintained for at least 5 minutes independent of the voltage supply in the vehicle.
The Telematic Communication Box (TCB) monitors the emergency battery within the framework of an internal self-test after each start-up procedure. The emergency battery has a service life of at least 5 years. If the capacity of the emergency battery is exhausted to the extent that placing an emergency call can no longer be guaranteed then this is shown by a Check Control message (emergency call system fault!). A fault entry is also stored in the Telematic Communication Box.
Microphone
Depending on the series and the vehicle equipment, two microphones (microphone and microphone 2) are installed in the left and right sides of the roofliner. The microphone installation location can vary depending on the vehicle type. The microphone on the driver's side is always used for an emergency call.
The microphones work with full duplex transmission. This means that the audio frequency signals are activated for both parties. It is thereby possible to speak and listen during the same call.
The microphone on the driver's side is connected to the Telematic Communication Box (TCB). The microphone signals are forwarded to the headunit for the hands-free mode of the telephone system.
The microphone 2 for speech processing (if part of the equipment) in the roofliner on the front passenger side is then directly connected to the headunit.
Functional networking
The following functional networks are described:
- Telematics and connection to the headunit
Functional networking of telematics for headunit
System functions
Communication between Telematic Communication Box and headunit
For the transfer of telematics information the Telematic Communication Box (TCB) is connected to the headunit via a USB cable. The transfer is effected on the USB standard 2.0.
Notes for Service department
General notes
If the Telematic Communication Box (TCB) is programmed or the control unit is replaced, the online services have to be subsequently updated. This generally happens automatically via the programming system. It is possible to check this by selecting online services from the menu in the central information display.
A service function is available for updating the online services. This can be found as follows:
Service functions > 03 body > Telecommunications or headunit > Service update via diagnosis system
Diagnosis instructions
The state of charge of the emergency battery can be read via the control unit functions and the procedure for telecommunications. If the emergency battery needs to be replaced, a fault memory is stored.
The diagnosis of the USB connection between Telematic Communication Box (TCB) and headunit in integrated in the diagnosis of the headunit.
Function structure > 03 Body > Audio, Video, Navigation, Telephone > Headunit > Devices connected to headunit
We can assume no liability for printing errors or inaccuracies in this document and reserve the right to introduce technical modifications at any time.