BMW 5 Series: Ethernet

On the G30 the 2-wire OABR Ethernet (OPEN Alliance BroadR-Reach) from the G12 is used.

The Ethernet variant with 5 lines (4 data lines and 1 activation line) is still used on the G30 by the OBD2 interface to the Body Domain Controller.

Use of 2-wire OABR Ethernet on the G30

The following control units are connected to the vehicle electrical system via 2-wire OABR Ethernet in the G30:

• Active Cruise Control (ACC)
• Camera-based driver support systems (KAFAS)
• Top Rear Side View Camera (TRSVC)
• Rear view camera (RFK)

The following control units are additionally connected via 2-wire OABR Ethernet in the G30:

• Head unit
• Rear Seat Entertainment (RSE)
• Optional equipment system (SAS)
• Telematic Communication Box

Ethernet in the vehicle

The standard "Open Alliance BroadR-Reach" (OABR Ethernet) has been specially developed as a new data transmission layer for use in vehicles. OABR Ethernet only requires an unshielded twisted two-wire connection. OABR Ethernet supports bidirectional 100 MBit/s communication between 2 nodes. This means that both nodes can simultaneously send and receive at a data transfer rate of 100 MBit/s. OABR Ethernet requires point-to-point networking. This means that the bus system is not split up between multiple nodes, as is the case e.g. with Controller Area Network (CAN) systems.

Instead, Ethernet switches are used for the connection of further nodes. Today, Ethernet switches are integrated in the following control units: Body Domain Controller (BDC), Head Unit (HU), optional equipment system (SAS), Top Rear Side View Camera (TRSVC). An Ethernet switch (ENS) is used on the G30 depending on the vehicle equipment. In the event of failure of an Ethernet switch, all bus users connected by it are disconnected from the rest of the network and are no longer able to communicate via Ethernet.

Depending on the vehicle equipment, the control units are connected to the vehicle electrical system in different ways.

On vehicles with Navigation, the data transfer takes place from the Head Unit High to the instrument cluster via an APIX data cable.

Depending on the vehicle equipment an Ethernet switch may in some cases be required.

A wake-up line may be required for control units that are only connected to the Ethernet and are not additionally connected to a body CAN.

Control units on the Ethernet cannot be woken up via the bus. Instead, the control units are activated via the wake-up line or switched directly via terminal 15. As a result of the activation via a wake-up line, so-called partial network operation is also possible. In partial network operation, individual control units can switch to a rest state in different vehicle conditions.

The Ethernet topology of the G30 is listed below.

Ethernet topology with Head Unit High

In the wiring diagram the connection of the Top Rear Side View Camera (TRSVC) control unit and rear view camera (RFK) is shown. In the vehicle, either TRSVC is installed for a vehicle with multiple cameras, or RFK for a vehicle with a rear view camera (standalone).

On vehicles with Head Unit High, the Telematic Communication Box (TCB) and the Rear Seat Entertainment are directly connected to the head unit. The data transfer from the Head Unit High to the instrument cluster takes place via APIX. The instrument cluster does not require Ethernet. As a result, the Ethernet interfaces on the Body Domain Controller are sufficient, and no Ethernet switch (ENS) is required.

Ethernet topology on vehicles with Head Unit High

1. Top Rear Side View Camera (TRSVC)
2. Optional equipment system (SAS)
3. Active Cruise Control (ACC) Long Range Radar (LRR)
4. Body Domain Controller (BDC)
5. Camera-based driver support systems (KAFAS)
6. OBD2 interface (Ethernet with 5 lines)
7. Instrument panel (KOMBI)
8. APIX data line
9. Head Unit (HEADUNIT)
10. Rear Seat Entertainment
11. Telematic Communication Box (TCB)
12. Rear view camera (RFK)

The data transfer takes place from the Head Unit High to the instrument cluster via APIX connection.

Ethernet switch

Ethernet switch

The Ethernet switch is required for expansion of the Ethernet network. It connects the control units and forwards their data packages accordingly.

The Ethernet switch is not displayed in the bus overview by the BMW diagnosis system ISTA.

D-CAN

The D-CAN has a data transfer rate of 500 kBit/s.

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